AFAIK currently Gimp "renders" text layers (or uses a rendering found in the file) when loading PSDs and discards the text information. In any case a Gimp text layer only has text with font, style and size and doesn't include any effect, so either it is a quite simple text layer and you can redo it easily in Gimp (assumming you know and have the font) or its is a more completx text layer and Gimp doesn't support that anyway, from a PSD or natively..

Never used Photopea, but I read that you can convert PSD to Gimp's native format XCF. Did you try that?
If the text layer is rasterized, and I assume it will be I would simply redo the text in Gimp.