I agree with the others that the light can only tell you that a problem exists and that the ABS is disabled. We cannot even begin to guess the nature of the problem.
The only way to find out about repairs is to visit a shop that handles ABS problems. Not all garages are willing to tackle that system. As for reading codes, don't waste your time trying for a free reading. The auto parts stores that offer this courtesy read only the driving computer. The ABS has a separate computer.
In the meantime, the ABS light will continue to burn. There is no urgency to tackle this problem since you still have normal braking. Many olders of older cars simply forgo repairs entirely on malfunctioning ABS. As long as there is no problem with state inspections, they prefer to decline the expense. This is an acceptable solution, IMHO.