Firstly, you can secure a customer’s acceptance of the agreement and report this information to Microsoft through rhipe PRISM portal. (Available from December 1st 2019).
Secondly, you can invite a customer to accept the agreement through an authenticated Microsoft portal (Available from Jan 2020 onwards).
Thirdly, partners can use functionality available PRISM portal to determine if a customer has accepted the agreement directly with Microsoft (Available in early 2020). Customers who have already accepted the agreement through Microsoft will not need to resign the agreement for purchasing in CSP.
As mentioned in other question, before Microsoft Customer Agreement is available for signing through PRISM portal from December 1st 2019 you should continue doing Microsoft Cloud Agreement attestation of the acceptance of Microsoft Cloud Agreement by your customer in PRISM Portal.