If you have reporting by both the original creditor and a debt collector, then each must be addressed separately, as each can only agree to deletion of their own individual reporting.
If your primary goal is removal of the collection, then the usual process is to make a pay for deletion offer to the reporting debt collector.
However, if your primary goal is removal of the charge-off, then the process is make a pay for deletion offer to the original creditor.
Then make a good-will request to the other party for voluntary removal of their separate reporting.
However, if you have been contacted by a debt collector 2 while a collection reported by debt collector 1 shows in your credit report, you may have an option that will provide deletion of both without a good-will to the non-PFD party.
If a debt collector 1 has had their collection authority terminated, such as by decision of the creditor to reassign to a second debt collector, then that provides a window that may enable removal of the reported collection.
CRA reporting policy instructs a debt collector to delete their reported collection if their collection authority is terminated and the debt remains unpaid. Thus, you could contact he OC and make a PFD offer to them in addition to their agreement to also terminate the assignment of collection authority to debt collector 2 before they report.
Creditors are often reluctant to terminate collection authority based only on a consumer promise to pay, but it might be an option worth pursuing.