Laravel - need PHP code integrated into existing codebase

We have an existing working piece of PHP code that simply outputs a number - the current amount of BON SLP that the user owns in their wallet. We would like the code to be integrated into the site, such that when you call the variable $tokenBalance you are given the amount of BON SLP the user has. This way we can change the "BON:" display to be based on the SLP token instead of stored in MySQL.

This is the specific view we are targeting:

https://github.com/HDInnovations/UNIT3D-Community-Edition/blob/master/resources/views/partials/userbar.blade.php#L96

The code and full description is here: https://docs.google.com/document/d/1LVRNJHGJWg-p6BnIJkcigYGe81MQjy3svza81jO8pSI/edit?usp=sharing