Hello Community,
this is my first tutorial. I think it fits in here, doesn 't kill me, I was always sorry to explain the same * fg Its simular to this Posting form TheStonedTurtle maybe for others easier to use or not 
1. Copy the steamprofil link, it looks like
Open your friendlist, double leftklick on your avatar, your profil will open. There you press right mousebutton and copy url. It looks like:
Profillink without SteamID64
https://steamcommunity.com/id/Nickname
or
Profillink with SteamID64
https://steamcommunity.com/id/765611980xxxxxxxx
You need the SteamID64!
2. Got your steamID64
If you’ve the SteamID64, copy it and go on with step 3. If not, open steamid.io and insert your Profillink without SteamID64 and press the button “lookup”. You git it!
3. Transform your steamID64 to steam:hex
Open Binaryhexconverter and insert your SteamID64. Press the button “convert”. You got a Hexadecimal Value, like “1B33334D3DAAC0”.
4. Change letters
Change all uppercase letters to lowercase letters and write “steam:” in front of. For example “steam:1b33334d3daac0”
You got your steam:hex, hope it helps you.
Have a nice FiveM-Day
NebelRebell