uArm Polar Command Not Working

Hello,

This command works:
swift.send_cmd_async(msg=f"G1 X{x_str} F250")

This command does not work (the arm does not move):
swift.send_cmd_async(msg=f"G2201 S{s_str} F250")

Can you tell me why?

Hello,
Please provide specific assignments for x_str and s_str.