Hi. Couldn't find any license for mannequin. Am I allowed to sell character .png .svg file I made using mannequin and it's assets?

The license is available in the 'About' menu (button at the bottom right, marked by 'i' inside a circle).

Generally characters you made using Mannequin is permitted for commercial purposes, including selling the character as-is. Uses that is prohibited at the moment is anything related to NFTs or blockchain, due to the gray/uncertain concept of ownership that is understood among those who are involved in the space.

However, we kindly remind you that selling your character without any significant modification is very likely a bad business. If your client find out about Mannequin in the future and know that they are able to create multiple similar characters at the price point (or even free), they will very likely get disappointed.

OOps. Didn't look there. I am sorry. Thank you for making it clear to me. And: you're right. I didn't want to disappoint anyone.
btw: When may we get "older" faces and bodies?  (in mannequin perhaps ;-) )