Windshield wiper blade

1. Remove the cowl top vent panels. 2. Remove the mounting arm and pivot shaft. 1 Disconnect the electrical connector. 2 Remove the bolts. 3 Remove the mounting arm and pivot shaft. INSTALLATION 1. To install, reverse the removal procedure.

There are couple of reasons for the wiper not to work on one side.
There is a nut that keeps the wiper arm to the wiper gear, that nut could have come loose. So first make sure it is secured.
Other possibility is stripped out spline on either the wiper arm or the base.
If the spline is worn off on the wiper arm, replace the arm. If it is worn on the gear assembly, that assembly needs to be changed.

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.

https://www.2carpros.com/articles/how-to-replace-windshield-wiper-blades