Associate-SPFxFieldCustomizer.ps1

############################################################
# Set here the URL of your site
$targetWebUrl = "https://yourtenant.sharepoint.com/sites/yoursite"
# Set the name of the custom action here (do not really matter in this case but allows to identify it)
$customAction = "ImportantMarker"
# Set here the Id of your extension. You can find it in the manifest in your SPFx solution
$componentId = [GUID]"42887c3b-0b7c-4fc4-8510-1107c73495c9"
# Set here the Id or name of the list
$listNameOrId = "MOTD"
# Set here the internal name of the field to bind the extension to
$fieldInternalName
############################################################
Connect-PnPOnline $targetWebUrl
$list = Get-PnPList $listNameOrId
Set-PnPField -List $list -Identity $fieldInternalName -Values @{ClientSideComponentId=$componentId}