Create API connection for an embedded signature

I need a developer who is experienced working with the API connector to create an API connection for an embedded signature. I have tried to create a new connection, but I am getting an OAuth2 error.

Hi David,
I am a experienced developer and would be able to help you out on this…
You can reach me on andrewjohnson56782@gmail.com
Best Wishes,
Andrew

Hi David,
I would be glad to assist you.
Please connect me on Skype:cis.am2 or Email me:anna.cis23@gmail.com for a further discussion. I am sure the price will be very reasonable.
Looking for your reply.
Warm Regards,
Anna