This depends on how you are using the app.
If you have a connected bank account, you are either asked to perform an in app transfer to the bank account. If your bank only gives the Gimi app viewing but not transaction privilages, you can manually perform a transfer through your bank application of choice and then mark the payment as completed in the Gimi app.
If you are using the Gimi app with the Demo account only, the allowance total will be added to the demo account automatically on the allowance date. Note that since the money in the demo account is not tied to any real funds, this only means that the sum increases. You would still need to arrange for a way for your child to be able to use the total available to them, as shown in the demo account.
If you are a Gimi Master user, you'll be prompted to transfer the total allowance sum to the Gimi card on or after the allowance date. You can also choose to skip an allowance if so desired.