Question: Duwa's workshop

[Ilse]

I just unlocked the workshop of the sea people and can now buy stuff there, but how do I use it?? I can't find how I can have Duff make/enhance weapons with the sea people stuff. The story seemed to suggest that Duff would make me a cool new weapon

[Ǵ̶͓̂͑lí̴̤̀̄́tcĥ̸]

At some point as you continue the main quest line you will get to make a phone call. I believe it's when you can go down into the thermal area, but I cannot quite recall. Might be earlier.

[C-Bass]

For me, immediately after I unlocked the workshop and could buy things, I had a quest to "call Duff". I called him and that's when he told me about his new ability to upgrade weapons.

[Stygger]

You should get the option to upgrade weapons to a new final level at Duff now or tomorrow. The new upgrades require the Workshop equipment plus special ore. Don't worry about upgrading the same day as you unlock the workshop, because you most likely don't have enough ore anyway.

[Ilse]

Originally posted by Stygger:

You should get the option to upgrade weapons to a new final level at Duff now or tomorrow. The new upgrades require the Workshop equipment plus special ore. Don't worry about upgrading the same day as you unlock the workshop, because you most likely don't have enough ore anyway.

I am already at least one day further now, is it something that should pop up in the weapon shop app somewhere? I feel like I had all the dialogue (I called Duff about it), but Im not seeing the option anywhere.
As for story, I just got into the glacial area and found a stone slab