what do i do if I get the message blind spot system not available?

This could be a bad sensor, control module, wiring, etc. You need to start with a complete scan of the system. A professional scanner is required for this so you may need to use this link to find a good shop near you. Also, check your owner's manual in case they have a section on warning messages like this. Sometimes it can be a setting or something along those lines. Alex https://repairpal.com/repair-shops