I am looking to apply for a new job, and it seems like I have part of the background needed.

Part of the job asks for skill A, which my whole background is rooted in.

But, the primary function seems to be skill B.

I have some experience with skill B, but not enough where I am confident in my qualifications for the role.

While this new job (for a new team) seems to require more of skill B at the moment, I wouldn't be surprised if they start looking to hire more personnel with skill A down the line, as a supplement.

Essentially, they would want someone who has both skill A and skill B (more of skill B). But would they be open to someone who has high proficiency with skill A as well

How can I prove that my strength in skill A, and some experience with skill B is valuable to them?

And if I can't prove my value at this time, would it be possible to prove that skill A will be an integral function to have for their team later on (planting a seed for future openings)?