How to apply the same adjustments to multiple images?

[PixLab]

Like Tas_mania, I do it with G'MIC but in a different way, I use G'MIC as plugin > https://gmic.eu and I have a plugin to export layers as image/file there > https://khalim19.github.io/gimp-plugin-export-layers/
Once installed, open GIMP, import your images as layers, go to Filters > G'MIC, a window opens, do your thing, once happy  do not click OK, yet, but in the "Input Layer" select "All", then click OK, all layers will have the same adjustment.

   

Then I go to File > Export Layers...
Done.