Hello
Assuming your husband already has his own Microsoft account, right?
If so, hold down Win+R keys, type in netplwiz and press enter.
When it is launched, go ahead and click on Add. Then log into his Microsoft account. Finish the steps and it should create a new user on this computer for him to log in with his Microsoft account.
If you want to give him admin access, then on the netplwiz window, double-click on his user, go to the Group Membership tab, and make him administrator there.