In the sketch environment of fusion 360 there is five major types of lines
Construction lines, dotted.
Locked lines, green
Unlocked, blue
And fully constrained, black.
Projected lines, purple
You do not need fully constrained lines to create toolpaths.
The videos I showed up above here shows doing it with a fully unconstrained drawing. All blue lines.
You can extrude any lines that make a closed loop and produce a profile face.
You’ll be able to tell this by everything inside the lines being shaded a very light blue and when you move your cursor over it it will highlight to a darker blue.
If you’re looking for more specific help please post your drawing or a DFX or an SVG or a f3d something like that to get us started.