Missing UVs, Detected!

Question

I'm trying to texture paint a character in Blender, and I am loosely following a tutorial, just so I know what I'm doing. So this is what I've done:

1. Went to the Texture Paint tab.

2. Created a new material (on my character) and then in Base Color, clicked on the dot on the right side and then clicked Image Texture. I then created a new texture with the size of 2048px.

3. In Object Mode, I clicked on the Shading arrow on the right, near all the viewport shading buttons, and then clicked Flat.

4. (This was either step 3 or 4,) but I saved the texture and placed it near my .blend file.

That's where I stopped, because it gave me the warning. This is the current screenshot of what the editor looks right now:

I've searched on the net already, and saw this article, but the suggestions weren't really helpful.

Also in the same question, I was wondering how the person got this:

Menu to show, as the GIF was to fast for me to catch it.

Also I have seen these questions:

1. I am not able to use texture paint (2.8)
2. missing files blender 2.82 Missing UVs, Textures, detected!

But none of those worked. In the question number 2, I did try to change mode to Single Image, but nothing worked.

Maybe I'm changing it in the wrong place?

Answer 1

I've finally fixed the problem in the answer to this question. I needed to click Add UVs and then upload the (blank) texture I had.

In the tool bar, I clicked Draw and then it gave me the options to paint the character.

However, I had another problem, which is that when I try to paint my character, the paint did not show. I fixed it by this answer.