Flip edge in Equator layer but there is yellow in every edge in top layer

A way to solve this is to replace the flipped edge by a random block , but in my case all random block have yellow color, so if I swap than yellow will come in middle layer, which should not come there.

I am a absolute beginner

Replace it with a yellow-whatever random block anyway: the orange-blue edge will get to the top layer.
put the orange-blue edge back in its place (of course with the correct orientation), the yellow-whatever will get back to the top layer.
• The side with the yellow pieces is the top. (The cross is white and at the bottom. The enemy gate is down. $2+2=5$.) – Bass Jan 26 '20 at 16:49