Install lock on electrical panel
Your panel already has the knockout for a lock.  It is immediately above the latch.
See graphic.

Read the label, it calls out the Siemens part number for a lock kit.
Or you can bring the deadfront to your locksmith and I'm sure they can figure something out.
Remember, it is illegal to deny a tenant access to their circuit breakers.  A locksmith may be able to build a lock that operates on a tenant's key.