You can ask, but I don't know if they can do it or will do it under the circumstances. Unless they know how and are willing, you are basically in the position of a person purchasing a second-hand phone that is not ready for resale, and the phone will be useless to you.
Before you buy an iPhone, iPad, or iPod touch from someone other than Apple or an authorized Apple reseller, make sure that the device is erased and no longer linked to the previous owner’s account.
And see: Activation Lock for iPhone, iPad, and iPod touch https://support.apple.com/en-us/HT201365 See this heading Check for Activation Lock before you buy a device from someone else.