What ice is telling you
A frozen evaporator coil usually means the coil temperature dropped below the point where moisture freezes. A dirty filter is one possibility, but low airflow from a blower, duct, or coil can do the same.
What to do today
Switch cooling off and allow the ice to melt. Check the filter and look for water near the pan, but do not chip ice or keep running the system.
When service is needed
If the coil freezes again with a clean filter and normal airflow, the cause needs testing. A technician may check airflow, coil condition, refrigerant performance, blower operation, and the drain.
Do not assume low refrigerant
Low refrigerant can cause freezing, but refrigerant is not consumed like fuel. A leak or another system fault must be found before adding refrigerant is treated as a complete repair.
Prevent the next freeze
Keep the return path open, replace filters on schedule, and do not block supply vents. If freezing repeats, ask for airflow and refrigerant testing rather than another temporary thaw-and-restart.