I'm using the 1.13 edition of the 1.7.10 version of the Advent of Ascension mod, and when I go to look in the spawn menu, search bars via the vanilla menu and NEI menu, and there are only spawner blocks for the mobs in AoA, no spawn eggs.
I don't know if I am the only one with this problem but It would be a great help if someone can help me fix this problem
I presume you mean version Tslat 1.1.3. Spawn eggs do not exist in that version. The only way to get around that I know of is to install a different mod/addon that adds the spawn eggs in (the only mod that I know of that did that was called Silk Spawners, but I don't know if it exists anymore), or update to 1.12.2, which does have spawn eggs.