I tried doing methods like :
https://region.api.riotgames.com/lol/summoner/v4/summoners/by-name/Executioner?api_key=mykey
I even tried all regions but couldnt find a fitting summoner level to mine so what do I do probably wrong is my Summoner name something different?
my Ingame name is "Executioner" which I tried to use of course and my current level is 53 close to 54
Summoner names are no longer used in League of Legends. They've recently transitioned to Riot IDs, which you should've seen in a popup in the client.
These days, you're required to use the '/riot/account/v1/accounts/by-riot-id/' API, like this: https://europe.api.riotgames.com/riot/account/v1/accounts/by-riot-id/ietsrondsofzo/gamer
Of course, replace "ietsrondsofzo" with your own riot name, and the "gamer" part with your own tagline. You can find these on your profile by clicking the 2 boxes next to your name.