It seemed easy at first glance.
But after playing around a bit, I wasn't able to reproduce this type of outline using GIMP.
The technique shared by Sallyanne is the natural option for this type of effect. But as Ofnuts noted, maintaining the sharp angles as seen in the original example is what makes this a challenge.
I tried to explore a slightly different way, which consists of enlarging the path and not the selection, here's a little explanation:
When passing the text to the path, I used the Ofnuts plugin (Break text path apart), and enlarged each letter separately. In the end, I still needed to move the text down a bit and use the eraser to erase some internal parts (the middle of the letter A and the part between the I and the X).
I didn't like the result. I don't know if the technique would be correct and I wasn't able to apply it.
I think there's a better chance of good results using Inkscape.
Result below made with Inkscape version 1.4
But after playing around a bit, I wasn't able to reproduce this type of outline using GIMP.
The technique shared by Sallyanne is the natural option for this type of effect. But as Ofnuts noted, maintaining the sharp angles as seen in the original example is what makes this a challenge.
I tried to explore a slightly different way, which consists of enlarging the path and not the selection, here's a little explanation:
When passing the text to the path, I used the Ofnuts plugin (Break text path apart), and enlarged each letter separately. In the end, I still needed to move the text down a bit and use the eraser to erase some internal parts (the middle of the letter A and the part between the I and the X).
I didn't like the result. I don't know if the technique would be correct and I wasn't able to apply it.
Result below made with Inkscape version 1.4
.....
Samj Portable - Gimp 2.10.28 - Win-10 /64.
Samj Portable - Gimp 2.10.28 - Win-10 /64.