"To reinforce the behavior" means to increase the likelihood of a certain action or behavior happening again in the future by providing some kind of reward or consequence. Full definition
Don't accidentally reinforce the behavior by freaking out. (houstonpettalk.com)
This will not only reinforce behaviors already learned, but will strengthen the bond between you and your dog as well. (animalbehaviorcollege.com)
You want to be careful that you don't reinforce his behavior since any negative attention he gets for doing this can reinforce it. (verywellfamily.com)