Using flow to populate a field in a record using a value from a record in another module

In Zoho CRM, I have used the Products module to enter products with associated commissions that are paid for each product.

I use the Deals module to set up deals for a contact. The deal template has a lookup field for the Product. There is also Commission Amount field in the deal, and for now the commission amount must be typed in the field.. I would like to automatically populate the Commission Amount field in the Deal record with the commission that is in the Product record for the Product in the deal.

I would like for this action to occur anytime a Deal is created or changed.

Secondly, I would like to set this up so that if the commission amount is changed for any Product, any Deals that include this Product would be updated with the new commission amount.

Thanks for any guidance on how to perform either or both of these.