Which government issued your actual domestic drivers license? The international drivers licenses issued to US citizens before they leave the US to travel abroad will not have a statement to “allow” the driving of a manual vehicle. That is because you are not issued your home drivers license with such an allowance. When you receive your actual drivers license, it automatically allows you to drive manual or automatic regardless if you have experience with a manual transmission. If you are restricted due to health or disability, it will only show that restriction.
As an American renting cars overseas, I have been asked by the rental agencies if I can drive manual. They ask because it is neither on my international nor my domestic license. They also ask because it is increasingly uncommon for Americans to know how to drive manual. Automatic transmissions are ubiquitous in the US. Some even consider automatic transmissions to be “standard”. Some foreign car manufacturers have stopped importing manual transmissions to the US. In recent years, I have had to special order manual transmission cars directly from the factory. Even having a valet park my manual transmission car has been a problem.