invocable method in Flow to Update Custom Metadata Type

customMetaDataCallBack

//https://www.biswajeetsamal.com/blog/create-or-update-custom-metadata-type-using-apex/
public class CustomMetadataCallBack implements Metadata.DeployCallback {
     
    //Inteface method 
    public void handleResult(Metadata.DeployResult result, Metadata.DeployCallbackContext context) {
        if (result.status == Metadata.DeployStatus.Succeeded) {
            //Success
        } else {
            //Failed
        }
    }
}

CustomMetadataUtils

//https://www.biswajeetsamal.com/blog/create-or-update-custom-metadata-type-using-apex/
public class CustomMetadataUtils implements Metadata.DeployCallback {
     
    //Interface method 
    public void handleResult(Metadata.DeployResult result, Metadata.DeployCallbackContext context) {
        if (result.status == Metadata.DeployStatus.Succeeded) {
            //Success
            System.debug('Success Result-' + result);
        } else {
            //Failed
            System.debug('Failed Result-' + result);
        }
    }
     
    //Create Custom Metadata record
    public static void createCustomMetadata(String metdataName, String label, Map<String, Object> metadataFieldValueMap){
        String recordDevName = label.replaceAll(' ', '_');
        Metadata.CustomMetadata cMetadata = new Metadata.CustomMetadata();
        cMetadata.fullName = metdataName + '.' + recordDevName;
        cMetadata.label = label;
         
        for(String key : metadataFieldValueMap.keySet()){
            Metadata.CustomMetadataValue cMetadataValue = new Metadata.CustomMetadataValue();
            cMetadataValue.Field = key;
            cMetadataValue.Value = metadataFieldValueMap.get(key); 
            cMetadata.values.add(cMetadataValue);
        }
         
        Metadata.DeployContainer mdContainer = new Metadata.DeployContainer();
        mdContainer.addMetadata(cMetadata);
        CustomMetadataUtils callback = new CustomMetadataUtils();
        Id jobId = Metadata.Operations.enqueueDeployment(mdContainer, callback);
    }
     
    //Update Custom Metadata record
    public static void updateCustomMetadata(String metdataName, String recordDevName, String label, Map<String, Object> metadataFieldValueMap){
        Metadata.CustomMetadata cMetadata = new Metadata.CustomMetadata();
        cMetadata.fullName = metdataName + '.' + recordDevName;
        cMetadata.label = label;
         
        for(String key : metadataFieldValueMap.keySet()){
            Metadata.CustomMetadataValue cMetadataValue = new Metadata.CustomMetadataValue();
            cMetadataValue.Field = key;
            cMetadataValue.Value = metadataFieldValueMap.get(key); 
            cMetadata.values.add(cMetadataValue);
        }
         
        Metadata.DeployContainer mdContainer = new Metadata.DeployContainer();
        mdContainer.addMetadata(cMetadata);
        CustomMetadataUtils callback = new CustomMetadataUtils();
        Id jobId = Metadata.Operations.enqueueDeployment(mdContainer, callback);
    }
}

Invocable Action

//primary source https://www.biswajeetsamal.com/blog/create-or-update-custom-metadata-type-using-apex/

//I update a custom metadata type from Flow with an invocable action because I can't do it directly. 

public class invokeUnsubscribeJan2021 {
    
    //Flow screen takes information and passes to this invocable method
    @InvocableMethod (label='Create Unsubscribe Record Jan2021'description='CreateUnsubscribe')
    
    //pass a list of records from the flow, but it's actually just one record
    //the type of variable being passed is a record variable of a custom metadatatype
    public static void Unsubscribe(List<Unsubscribe_Link__mdt> recordPassed) {
        //declare a new map
        Map<String, Object> metadataFieldValueMap = new Map<String, Object>();
        //add values to the map of Field Name on CMT and value passed in from the Flow
        metadataFieldValueMap.put('Our_Organization__c', recordPassed[0].Our_Organization__c);
        metadataFieldValueMap.put('Site_Domain__c', recordPassed[0].Site_Domain__c);
        
        //call the class and method to update the CMT
        CustomMetadataUtils.updateCustomMetadata('Unsubscribe_Link__mdt', 'Unsubscribe','Unsubscribe', metadataFieldValueMap);
    }
}