Help with Success Plan Creation API JSON

Hi! I’m looking for help with my JSON on a Success Plan Creation API external action. I am attempting to create a Success Plan that is linked to a Relationship and where I populate a lookup field to a custom object. I am receiving an error attempting to create that says,

“Please enter valid JSON and char limit should not exceed 10,000.”

I know I have not exceeded the char limit. I copied/pasted the original JSON template from the Support website, made edits in Notepad++, and then copied/pasted back into the Payload for an external action. When I put this into a JSON validator website, it is showing many errors, but none that would help in fixing the issues.

My JSON is as follows:

{
    "requests": [
        {
            "record": {
                "referenceId": "1",
                "Name": "{{SPName}}",
                "SFDCID": "{{CompanySFDCID}}",
                "OwnerEmail": "{{SPOwnerEmail}}",
                "DueDate": "{{SPDueDate}}",
                "SuccessPlanType": "Digital Solution Onboarding",
                "status": "Active",
                "Templates": [
                "Phase 1: Digital Solution Sale"
                 ],
                "RelationshipID": "{{SPRelationshipID}}",
                "Onboarding_Data_Entry_Record__gc": "{{DODEGSID}},
            }
        }
    ],
    "lookups": {
        "OwnerId": {
            "fields": {
                "OwnerEmail": "Email"
            },
            "lookupField": "Gsid",
            "objectName": "gsuser",
            "multiMatchOption": "FIRSTMATCH",
            "onNoMatch": "ERROR"
        },
        "CompanyId": {
            "fields": {
                "SFDCID": "SfdcAccountId"
            },
            "lookupField": "Gsid",
            "objectName": "company",
            "multiMatchOption": "FIRSTMATCH",
            "onNoMatch": "ERROR"
        },
        "RelationshipId": {
            "fields": {
                "RelationshipID": "Gsid"
            },
            "lookupField": "Gsid",
            "objectName": "Relationship",
            "multiMatchOption": "FIRSTMATCH",
            "onNoMatch": "ERROR"
        },
        "Onboarding_Data_Entry_Record__gc": {
            "fields": {
                "DODEGSID": "Gsid"
            },
            "lookupField": "Gsid",
            "objectName": "Digital_Onboarding_Data_Entry__gc",
            "multiMatchOption": "FIRSTMATCH",
            "onNoMatch": "ERROR"
        },
    }

Please help if you can!

Thanks,

David Person