Salesforce Adobe Sign : Permission denied

Hi Everyone,

For one of our customer Adobe eSign feature is already implemented for internal users in Salesforce. Now we want to rollout the Adobe eSign feature to "Customer Community Plus" users (External users).

I gave all the object permissions. When I try to invoke following method "echosign_dev1.AgreementTemplateService.load( [AgreementTemplateId] , [RecordId] );" from my class, i was reported with following exception "Permission denied. Unable to insert field echosign_dev1__Recipient_Type__c in object: echosign_dev1__SIGN_Recipients__c" in debug logs.

Also I tried  Send "On Behalf Of" feature specified in the following document "Adobe Sign for Self Signing (Community Cloud) ". No Luck.

My question is: Will Adobe eSign work with Community user (External Users) ? If yes help me in resolving the above issue. If it doesn't support for external users what will be work around ?

Appreciate you help.