Yes - only one side of the connection needs to have a license 👍
If you make sure the license is active on your account and you are signed in to your account so that the license is being recognized by the software, there is no issue at all.
You can tell the supplier that he can, in any case, start the trial for commercial usage to test the software without the need to buy a license in the first place. This is totally fine and legally ok 👍
If he likes the experience, he can buy a license in a second step 🙌