A reason, not a calendar
The EPA does not recommend cleaning air ducts on a routine schedule. It suggests considering it when there is a specific reason: substantial mold growth you can see inside hard ducts or on other parts of the system, ducts infested with insects or rodents, or so much dust and debris that it is released from the supply registers. The EPA also notes that duct cleaning has not been shown to prevent health problems.
If none of those apply to your home, it is reasonable to leave the ducts alone and keep up with ordinary maintenance such as changing the HVAC filter.
Write down what you have noticed
Before you call anyone, note which rooms are affected, what you saw and when it started. Mention recent building work, unusual odors or any known water damage. These details let a contractor understand the concern without deciding the answer for you.
Ask to see the findings
Ask the contractor to show you what they found and explain why they think cleaning is or is not worthwhile. Photos tied to a specific part of the system are more useful than a general description.
Compare the whole proposal
A useful quote names the system, the work included, the method, what is excluded and the total price. Ask who will do the work and whether anything extra needs your approval first.
Airway can pass your request to an independent local contractor. The contractor assesses your home and confirms the scope, and you decide whether to book.