Use any portals to the Nether thanks to Smaller Nether Portals Mod 1.19.2, 1.18.2 in Minecraft. Now the dimensions of the portal you created do not matter as before.
Smaller Nether Portals Mod for Minecraft 1.19.2, 1.18.2
Many players have come across a rather strange decision by the game developers. It’s about creating a portal to the Nether and you can’t create portals that are too small (although large ones work). So we have a problem with lack of obsidian sometimes. You may simply not have enough obsidian in vanilla survival. But do not be sad because now you can create a portal to the Nether using always a couple of blocks of obsidian. Of course, this is a cool solution that facilitates the gameplay.
Forget about the long search for obsidian, which usually takes hours. You only need a few blocks that you need to lay out in the format 2×2, 1×3 or 1×2. Your portal will work and this will certainly create new conditions for you. Of course, this is a useful modification that will be useful to everyone.