Change edge index

Hi everybody. Help me, please.
I want change index of selected edge to 1, but if i convert bmesh to mesh - index will change to 3. Where did I go wrong?
I assumed it was impossible to just assign indexes and tried to do this by shifting the sequence, but it didn’t help :c

Indices of BMesh elements are internal. While you can change them temporarily, the changes should not be expected to persist. All sorts of internal tools and operators in Blender reset the indices to be the current order of the elements in internal arrays.