I'm ashamed, but I don't know how to open a portal! :(
What's the deal.

Which portal are you talking about?
If it's about the spell, then in the game on SoD, to get to any free town, you need advanced earth magic and wisdom level 4 to learn the spell itself. On TE, instead of earth magic, you need fire magic.
If it's a portal in Inferno castles, then they need to be built in several such castles, otherwise they are useless.
If it's a summoning portal in the Dungeon, then it allows you to hire creatures if there are external dwellings. If there aren't any, then it doesn't work at all!

Added after 6 minutes

Yes, WoG 3.58f. All that remains is to install TE. I didn't quite understand, the rules say that you need to download a 30 MB archive, but on this site I only found "Full Russian version of TE 1.03f" (845KB) at the URL http://heroesv.net.ru/up_files/hmm/wog/te/TE1.03f_rus_heroesV.zip
Is this enough? If not, please provide a direct link to what is needed.
Although the quests work even on WoG 3.58f.
Thank you very much for your answers.

To participate, you need to read the rules:
/topic/102/
In addition, playing on WoGe is not allowed by the rules; you need either SoD 3.2 or TE 1.03p. The game version has been slightly updated compared to TE 1.03f, and you need to install the update.
Today it's best to start with the clan tournament, but you can also play any quest from the arena tournament. Or you can do everything at once!!!
Good luck!