I want to cancel the zoho mail service customer number 20060087524

I want to cancel the zoho mail service customer number 20060087524

On February 2nd of this year I bought the zocho mail service for myself and my family. Apart from the mail client via the zoho application, it does not work for me on the iPhone and iPad. I want to cancel, what is the procedure?

 klient number: 20060087524
Regards
Marek Sajdak