ESA Work permitted form for self employed

hi I’m wondering if anyone can help

I am currently getting ESA payments and I’m looking to start a new job which I will be a self employed contractor for a cleaning company

I’m in the process of filling the work permitted form out but I’m stuck as it asks for employer details. I didn’t want to leave this blank and it come back but as I’m self employed what should I put in this?

I have been sent a contractor agreement by the company which states to never give out their details so I’m not comfortable with putting them in the employer section.

Please could someone help?! TIA