Hello Duwoaduf24
Welcome to the Community.
As a general remark, we do not recommend purchasing tickets with Trainline. You should rather purchase it with the train operator. SBB cannot change tickets from Trainline.
E-tickets are personal, they must bear the name of the person travelling. You cannot travel with two tickets for the same person. The same rules do apply as with air tickets.
Unfortunately, you have to purchase a new ticket for your husband.
Kind regards,
Roland