trouble using minecraft commands.

[isaiahxa]

im very sorry if this is the wrong place for this. but when i am playing minecraft, im unable to use any commands where a - is utilized, such as teleporting or setting spawns using negative coordinates. i do these through the console of my minecraft server, and i cannot find out how to either

a) completely remove rcon-cli from the server,( i never used it before transferring to a free service called seedloaf, and when i used other services like aternos, it worked fine, but i migrated from this service because of the bombardment of ads)

or

b) somehow change the character that initiates rcon commands from the - to an ! for example.

i hope this makes sense, and maybe someone would be able to help me, thanks so much, i apologize again. here is an example of the message i recieve when trying to use a teleport command: