https://github.com/analytics-debugger/google-analytics-4-for-amp/blob/main/ga4.json

ga4.json

{
    "cookies": {
        "_ga": {
            "value": "$IF(LINKER_PARAM(_gl, _ga),GA1.0.LINKER_PARAM(_gl, _ga),)"
        }   
    },    
    "linkers": {
        "_gl": {
            "enabled": true,
            "ids": {
                "_ga": "${clientId}"
            },
            "proxyOnly": false
        }
    },
    "triggers": {
        "page_view": {
            "enabled": "${DEFAULT_PAGEVIEW_ENABLED}",
            "on": "visible",
            "request": "ga4Pageview"
        },
        "doubleClick": {
            "enabled": "${DEFAULT_PAGEVIEW_ENABLED}",
            "on": "visible",
            "request": "ga4Dc"
        },        
        "webVitals": {
            "enabled": "${WEBVITALS_TRACKING}",
            "on": "timer",
            "timerSpec": {
                "interval": 5,
                "maxTimerLength": 4.99,
                "immediate": false
            },            
            "request": "ga4Event",
            "vars": {
              "ga4_event_name": "web_vitals"
            },
            "extraUrlParams": {
                "event__num_first_contenful_paint": "FIRST_CONTENTFUL_PAINT",
                "event__num_first_viewport_ready": "FIRST_VIEWPORT_READY",
                "event__num_make_body_visible": "MAKE_BODY_VISIBLE",
                "event__num_largest_contentful_paint": "LARGEST_CONTENTFUL_PAINT",                
                "event__num_cumulative_layout_shift": "CUMULATIVE_LAYOUT_SHIFT"                                              
            }              
        },
        "performanceTiming": {
            "enabled": "${PERFORMANCE_TIMING_TRACKING}",
            "on": "visible",
            "request": "ga4Event",
            "sampleSpec": {
              "sampleOn": "${clientId}",
              "threshold": 100
            },
            "vars": {
                "ga4_event_name": "performance_timing"
            },            
            "extraUrlParams": {                                      
                "event__num_page_load_time": "${pageLoadTime}",
                "event__num_domain_lookup_time": "${domainLookupTime}",
                "event__num_tcp_connect_time": "${tcpConnectTime}",
                "event__num_redirect_time": "${redirectTime}",
                "event__num_server_response_time": "${serverResponseTime}",
                "event__num_page_download_time": "${pageDownloadTime}",
                "event__num_content_download_time": "${contentLoadTime}",
                "event__num_dom_interactive_time": "${domInteractiveTime}"
            }  
        }                  
    },    
    "vars": {
        "documentLocation": "SOURCE_URL",
        "clientId": "CLIENT_ID(AMP_ECID_GOOGLE,,_ga,true)",
        "dataSource": "AMP"        
    },
    "extraUrlParams": {
        "sid": "$CALC(SESSION_TIMESTAMP, 1000, divide, true)",
        "sct": "SESSION_COUNT",
        "seg": "$IF($EQUALS(SESSION_ENGAGED, true),1,0)",
        "_et": "$CALC(TOTAL_ENGAGED_TIME,1000, multiply)",        
        "gcs": "$IF($EQUALS(${GOOGLE_CONSENT_ENABLED},TRUE),G10$IF($EQUALS(CONSENT_STATE,sufficient),1,0),)"                
    },    
    "extraUrlParamsReplaceMap": {
        "user__str_": "up.",
        "user__num_": "upn.",
        "event__str_": "ep.",
        "event__num_": "epn."
    },    
    "requestOrigin": "https://${GA4_ENDPOINT_HOSTNAME}",
    "requests": {
        "ga4IsFirstVisit": "$IF($EQUALS($CALC(SESSION_COUNT, $CALC($CALC(${timestamp}, 1000, divide, true),$CALC(SESSION_TIMESTAMP, 1000, divide, true), subtract), add),1), _fv, __nfv )",
        "ga4IsSessionStart": "$IF($EQUALS($CALC($CALC(${timestamp}, 1000, divide, true),$CALC(SESSION_TIMESTAMP, 1000, divide, true), subtract),0), _ss, __nss)",                
        "ga4SharedPayload": "v=2&tid=${GA4_MEASUREMENT_ID}&ds=${dataSource}&_p=${pageViewId}&cid=${clientId}&ul=${browserLanguage}&sr=${screenWidth}x${screenHeight}&_s=${requestCount}&dl=${documentLocation}&dr=${externalReferrer}&dt=${title}&${ga4IsFirstVisit}=1&${ga4IsSessionStart}=1",
        "ga4Pageview": {
            "baseUrl": "/g/collect?${ga4SharedPayload}&en=page_view"
        },        
        "ga4Event": {
            "baseUrl": "/g/collect?${ga4SharedPayload}&en=${ga4_event_name}"
        },
        "ga4Dc": {
            "origin": "https://stats.g.doubleclick.net",
            "baseUrl": "/g/collect?v=2&tid=${GA4_MEASUREMENT_ID}&cid=${clientId}&aip=1"
        }
    }
}