You are being very secretive. What board? Which emonCMS? How are you trying to connect? What are you trying to send? Does your data conform to the format that emonHub expects?
All the instructions for emonCMS are in the “Guide” section. This assumes you are using our standard set-up - an emonPi or emonBase, optionally receiving data from one or more emonTx or emonTH.
If you have anything different, then you must arrange to send your data in a compatible format. You should probably not change anything other than the configuration files in the standard emonHub/emonCMS combination to suit your sketch, but rather make your sketch compatible with our standard. That way, you will be able to update emonCMS without having to rewrite it every time.