Step 1
Check the amount that is currently in the tenant wallet by clicking their profile.

Step 2
If the wallet balance is to be used towards a bill, you can split the bill amount over 2 bill tasks.
For example, if the tenant owes $100 for water usage but only has $60 ib their wallet you can create a bill for $60 and another bill for $40. This will allow the wallet balance to be used.
If the wallet balance is to be used towards rent, add a credit of the difference between the rent amount and the tenant wallet amount.
For example, if rent is $1000 and the tenant has $800, add a $200 credit.
The rental amount will now be $800, and will be paid by the available funds in the tenant's wallet. Proceed to step 3.

Step 3
If you changed the rental mount you will need to Increase the next rental amount to capture the shortfall. You can do this in one payment or perhaps allow the tenant a few periods to catch up.
For example, If I added a credit of $200 on a $1000 payment, the next payment will be $1200.

Step 4
Finally, schedule the rent to go back to the normal level. You can add multiple rent adjustments so once you have added the first to claim the shortfall, you can add a second adjustment to return the rent to the normal level.
Other helpful articles: Adjusting rent, giving a rental credit