Behavior of two checkboxes where one must be selected [duplicate]

In a report settings area I am using 2 checkboxes where the user can select either or both, but one must be selected. We default to the most common option but if they unselect that one option and try to save their changes they will be greeted with some inline validation. I was thinking that we could remove the inline validation by implementing the following behavior; When one option is selected and the user unselects that option the other would automatically get selected. It would essentially be like a toggle but with the ability to have both states on at the same time. I haven’t been able to find any guidance or examples on this particular situation. It may be confusing to automatically select another option, but it would eliminate the possibility of not having an option selected at all. Is there any guidance on this scenario or examples anyone has seen? Thanks in advance.