Moving from personal business Apple IDs to Business manager

Good afternoon all,

We are looking at moving from personal-ized AppleID's that were used for business to apple's Business Manager system so we can centrally manage accounts.

I've been doing some reading on setting up ABM and I think we can do it, but my question has to do with apps that we have been purchasing under these individualized accounts. Do we lose them and need to repurchase, or is there a way to migrate them when we change from something like:

business-user@icloud.com

to something like the following in Business Manager:

user@businessname.appleid.com

thanks