If you are still having trouble, take a look here. Post 1 has quite good pictorial instructions.
https://funnyadultgamesplay.com/forum/index.php/topic,5027.0.html
Your banner must be 750 x 90 in size.
In the above topic is some banners you can use or use for ideas.
If you want to send your pics to me in PM, I can have a look at making you a banner.
By the way, the code visible in your signature should read [img.] [/img.] See the latter bracket has a forward slash and remove the . in both. I had to add . so you could see them.
You also need to have a http address on your pic / signature banner for it to show and use in forum.
These can be obtained by creating a free account with imgur.
For storing images and giving them a http address – Imgur https://imgur.com
