I think you need an input box instead of a text box for your date in that case, and you reset to default (=Today()) if 1 is selected in the dropdown.
Please let me know if this is not clear or does not work and I will try when I have time.
Reopen responsibly, monitor intelligently, and protect continuously with solutions for a safer work environment.
Check out the winners of the recent 'Can You Solve These?' community challenge!
Join us for an in-depth look at the new Power Apps features and capabilities at the free Microsoft Business Applications Launch Event.
Featuring samples like Return to the Workplace and Emergency Response Applications
Features releasing from October 2020 through March 2021