Yes, you can. You only need to purchase both OMPT-A and OMPT-F test attempts and schedule the tests (separately) via the integrated Examity button.
Consider sparing at least a one hour window between tests for the pre-checks, toilet break, have drink/food, and wind down your brain before moving on to the next test. You will have a different session, different proctor, and need to do pre-checks on each test.