Hello,
The recommended way is to go to the adapters list, then click on “Export”. This will output a .csv file with transactions, and the users are identified in that file using their email. Later, to import the csv file, go to Wallets -> Transactions and use the form at the bottom of the screen. The plugin will map the user emails back to user ids when importing transactions.
Did you attempt this? Did you encounter any problems? If so, please let me know.
with regards