No, provera is not designed to be absorbed across the vaginal mucosa.
If there are issues taking it orally it is available in injectable form as depo provera which is used as a contraceptive.
If you have been prescribed it as a standalone treatment e.g. to control bleeding this is fine (although bone density can be a concern with long term use in older reproductive aged women).
The depo provera injection has not been studied as endometrial protection within HRT and whilst in theory it probably would suffice this is very much non standard practice and should not be done without specialist guidance.
