How to load Pixmap/Texture into AssetManager?

I've come across those articles: https://libgdx.badlogicgames.com/nightlies/docs/api/com/badlogic/gdx/assets/AssetManager.html http://libgdx.badlogicgames.com/nightlies/docs/api/com/badlogic/gdx/assets/loaders/PixmapLoader.html http://libgdx.badlogicgames.com/nightlies/docs/api/com/badlogic/gdx/assets/loaders/TextureLoader.html https://github.com/libgdx/libgdx/wiki/Managing-your-assets

And I still didn't find anything about how to load a Texture into the AssetManager. In my game I create a Pixmap and wrap it around a Texture. Then I dispose the Pixmap. Then I draw the Texture with SpriteBatch. Every Texture created in my game has been created by a Pixmap, so it's created in runtime. How do I load those Textures into the AssetManager?

The links above and everything I've come across only show how to load Textures from already available files.