Do not, under any circumstances, use Expedia. We had to cancel flights at Christmas time due to Omicron and were given flight credits. When we tried to redeem them on the app - in January, for travel in summer - it only allowed for one-way bookings. When I logged into the desktop version, it has the same problem. Turning then to the chat bot for help, that is also thoroughly useless. If you want any hope of actual help, you need to ask for a live agent (not that you can speak to them - it's still on chat). So having worked out where we want to go and when, I have spent no less than three hours (literally) online only to be told the 'fare base' rules for our flight credits don't allow that. When I asked "what do they allow", all the agent can say is "pick a different date or destination" (which is not an answer to the question). In sum, no one is able to help you. This is a catastrophically horrible customer experience. Avoid this company like the plague.