Some general background about the plugin (this is not related to this particular coin adapter):
The user balance will change only if there is a deposit transaction debited to the user. For this to happen, the plugin must find an incoming transaction with a destination that is a user deposit address. i.e. the deposit address must have been generated via the plugin. To see which addresses are assigned to your user, go to Wallets -> Addresses in your admin screens.
You mention that you are not yet fully synced. There are two types of sync going on here:
1. Blockchain sync. This would be
TurtleCoind or equivalent.
2. Adapter sync. To see the progress you can inspect the WordPress transient mentioned before.
Both of these syncs must reach the height of the block where your transaction is.
For background info about what transients are: https://developer.wordpress.org/apis/handbook/transients/
If you install wp-cli on your server and navigate to your WordPress directory, you can then issue:
wp transient get trtl-TRTL-settings-max-height
to see up to what block the adapter has scanned for transactions.
Again, replace TRTL with your coin’s symbol. The first part of the blockchain that cointains no relevant transactions will be skipped. You can use this command to see the block where the adapter is at.
If all goes well, you should eventually see a deposit transaction for the user in your admin screens under Wallets -> Transactions, and the user will receive a deposit notification email.