I think I get this one now. It is really just as simple as
https://www.aliexpress.com/item/1005002876716833.html?spm=a2g0o.productlist.0.0.1d062cb76rdxa5&algo_pvid=a1f6f650-c05b-41ce-a62d-ededd7f42d31&aem_p4p_detail=202109082350463308814837441520040497998&algo_exp_id=a1f6f650-c05b-41ce-a62d-ededd7f42d31-0&pdp_ext_f={"sku_id"%3A"12000022647489999"}
it is not called level shifter and its colour is neither blue nor red and I was looking for a thing that looks like a board in blue/green/red PCB and hence the one I found.