At least add them on function return types and annotate types on common objects so that you don't have objects lingering with wrong property name/type or redundant properties that would be confusing to review.
It helps to create a type reference for your database schema, so you don't try to insert something weird or insert with missing columns.
Many people are doing TS wrong. They add types everywhere. Honestly, you should write as many types as necessary, but not more. Use type inference which works remarkably well.