If you are looking to create an agreement, check out the smart business box.

1.1.8.2 an onward transfer of Company Personal Data from a Contracted Processor to a Subcontracted Processor, or between two establishments of a Contracted Processor, in each case, where such transfer would be prohibited by Data Protection Laws (or by the terms of data transfer agreements put in place to address the data transfer restrictions of Data Protection Laws); An optional non-solicitation clause is included, which may help protect the business against customer-poaching by an errant subcontractor (http://wordpress.lescadeauxdecorinne.fr/2021/04/09/gdpr-subcontractor-agreement/