You can convert them to DDS, it's the better format to use for GameGuru, i was just giving you an example of the identifiers you need to use.
However, i've just realised that you're asking this in the EBE section. I'm not certain if EBE uses PBR or if it still just uses the old DNSI system, all the default textures for EBE are in DNSI format.
If it still uses the DNSI system you will need the following:
texturename_D.dds (this is your actual colour image map)
texturename_N.dds (this is your normal map)
texturename_S.dds (this is a specular map, you don't have a specular so the metalness renamed to texturename_S.dds should give a rough aprocimation)
texturename_I.dds (this is your emission map, note: it's an upper case "i" not a lower case "L")
no other maps work for DNSI textures
Give both versions a try and see what's better for you.
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