How to end ESA claim

I’m currently on Esa support group and SDP.

Although my health is no better, I’ve had enough and would like to start looking for a job for up to 25 hours whilst my son is at a specialist school (he’s autistic).

Am I able to apply for jobs whilst on my current claim?

Do I have to contact them when I start applying?

Or

Do I just call up and cancel the claim once I’ve got a job?

I don’t want to get into any trouble.

Thank you in advance.