This server uses a custom resource pack, made by LesserPuggles, l3rosiah, Micah_B12, SirPogsalot, and Hackogaming, with textures from Starmute for Incendium compatibility.
Although the server will automatically send you the latest version of the resource pack, that can take up a lot of time depending on your connection and you device's performance.
If you download the pack for yourself from the #resource-pack channel in the discord, you can then install it like a typical resource pack, then disable the server resource packs in the server browser.
To disable the server resource packs, simply go to your server browser, click PrometheumMC > edit (in the bottom left) > set "Server Resource Packs" to "Disabled".
Server resource packs disabled