Please be sure you're have the discord app installed and you use it or its open, otherwise you will not join the server.
Delete discord.bin in the Auth folder, which is located in your Synapse X folder, then restart Synapse.
If all fails, please DM any staff member. (staff located in the staff section)
They will ask you for proof, and what type (screenshare, and email). Usually they will ask for a serial key or screenshare proof of you using synaspe (script hub and etc.)