Modern inverters sometimes have no display on the front, only status lights. This can be confusing and irritating because the meaning of the lights is easily forgotten by the next time it comes up! Every inverter manual will contain an explanation of those lights – print a copy and post it somewhere near your inverter for reference.
If you have a Fronius Primo Gen24 inverter, it looks something like this:
And here is the guide to the status LEDs:
