Salesforce opportunity fields/values not showing in Marketo

[Anonymous]

We want to pass values for several (Salesforce) opportunity fields to Salesforce when users submit a form. We are pretty sure that using a flow is the way to do that - but the fields we want to use do not appear in Marketo.

Opportunity.Source__c
Opportunity.Source_Detail__c
Opportunity.Source_Date__c

Brilliant solutions/hacks/workarounds welcome.

Thanks   

[Anonymous]

Unless there is a custom way to handle this wtih API/Webhook I"m thinking this is something that will need to reside in SFDC. I would post to a group in SFDC Communities. The real issue is updating an Opp from a Contact, which do not have a parent-child relationship. One of the admin whizzes will be able to tell you if they have a custom trigger or automated csv update to accomplish something like this. 

[Josh_Hill13]

You can only read these in Marketo, you cannot modify them. This is why they do not appear on the Form editor.

You should use their precursors - Lead Source and LEad Source Detail.

It may be possible to handle this with the API or a Webhook, but this could be dangerous.