How to use cream for yeast

So I had a yeast infection a few weeks ago but my OBGYN recommended Nystatin and Triamcinolone Acetonide ointment because there’s still yeast down there. I’m just confused bc the medication says external use only. However, my OBGYN said don’t insert it all the way in me. I interpreted it as open the lips some and apply it but isn’t that considered internal? And I’ve seen things online saying this cream should not be used for the groin area. Has anyone else used this for yeast infections?