we have apple tv and my husband is traveling, can we both use it in different places?

Apple TV+ allows for simultaneous use on up to 6 devices per subscriber.

Apple TV+ keeps watch progress per Apple ID account. Multiple users that share one subscription, should consider setting up Family Sharing instead, so that each user gets their own watch progress, Up Next queue list, etc.

If you like to watch “together” (exact same time) in different places, then it must be done through different Apple ID account for each: SharePlay in combination with FaceTime. Somewhat similar to what other streaming services call ‘Watch Party’.

SharePlay: Watch movies and TV shows together in FaceTime on your iPhone or iPad - Apple Support

SharePlay: Watch and listen together in FaceTime on Mac - Apple Support

SharePlay: Watch together in FaceTime on Apple TV box - Apple Support

Apple SharePlay is not supported on third party devices.

If you are using Family sharing, he can already access the Apple TV+ subscription on his ow Apple ID.

He does not need to do anything beyond opening the Apple TV app or even logging in to https://tv.apple.com from any web browser with his own Apple ID.

He should not sign into your Apple ID for any reason.

You mention he does not have a device, then what would he be signing into?

If has an iPhone, iPad, Mac or Windows laptop and you are in fact using Family Sharing, he can access the Apple TV+ subscription through the Apple TV app on one of those devices using his own Apple ID.

The subscription is shared automatically over Family Sharing.

What exactly do you mean by you have "Apple TV".

Do you mean you have an Apple TV streaming Box?

Do you mean you have the Apple TV+ subscription?

Or

Do you mean you use the Apple TV app on your Smart TV, or other streaming device like a Roku or Amazon Firestick?

Also, are you signed in with your Apple ID when using "Apple TV' or are you signed in with your husband's Apple ID?

If using the same Apple ID, you may get an error if both of you try to watch something at the same time.

Otherwise, if each of you is using your own Apple ID, and just share the subscription (Family Sharing), you can use it without any issue.