If you want to wrestle a little, but much less than what's needed to be able to create and edit firmly SVG effects you can try this. Essentially it's already suggested by others in comments but here's some details. Let's have the next plan for our bevel:
NOTE: We have here colors only to keep the explanation clear. Our goal is a metallic looking grayscale object. It can be colored later as wanted.
In the left the red and green areas should be the edge slopes and the blue area should be the plain top. Green area is separated because it should have sharp corners against the red area. We want to adjust how much the border of the blue is rounded. That's why blue and green shapes overlap.
The blue shape is made by applying Path > Dynamic Offset to a copy of the red shape. The green shape is drawn with the pen. Later we call in the text the shapes of our plan with names Base C, Top C and Sharp End.
The next job is to select the wanted light direction. It's difficult to change it later. Our light comes from top right.
The next cartoon presents the building of the final bevel:
Draw with the pen generously oversized grayscale shapes which coarsely present the lights and shadows of our bevel. Shape Sharp End is used as one of them (=lifted to front). Oversize is needed because blurring (for easy gradients) makes a part of every blurred shape useless near its edge. Snap to node help drawing.
Shape Top C is lifted to front and colored to grey. The shading except shape Sharp End are grouped for easy blurring. All items are easily reachable via the Objects panel. Even clipped and grouped shapes can be selected individually.
The grouped shading pieces are blurred. The group has got blur with the blur slider of the objects panel
Hiding the extras: Shape Base C is lifted to front, all is selected and Object > Clip > Set is applied. It's a good idea to make a spare copy of Base C for coloring before applying Clip > Set.
Shape Top C is selected and filled with a gradient for better metallic appearance
Blur is inserted to Top C for rounded bevel appearance. Sharp End could get the same if needed, but the rounded corner would need a highlight zone for plausiblity. That should have been inserted in step 1. But a blurred white piece could be inserted also now. I skip it.
A copy of Base C is colored to yellow and placed on the top with blending mode Color. That's very poor gold. but acceptable non-polished brass.
The amount of work would be 90% less if one works in GIMP with a bump map or in Photoshop (or in free Photopea)with layer style Bevel & Emboss.