Bot crashes when mentioning someone with switch code command

[h3oCharles]

Describe the bug
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bot crashes when trying to find someone else's (not your own) switch friend code

To Reproduce
Steps to reproduce the behavior:
anywhere where this bot can see commands, send a message containing "r!sc" and @mention yourself

r!sc @h3oCharles{Enter}{Enter}

Expected behavior
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the bot would say the switch code of the person mentioned

Screenshots
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typing "r!sc" without anything else does what it's expected

however, sending the same command with mentioning myself doesn't output anything

after some time passes, the bot becomes offline

Additional context
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