How to find out sub-options under a module's option when using GMT in julia?

I’m new in GMT.jl. I follow the examples from Tutorial in Julia — GMT 6.4.0 documentation, and make a geographic map with a image pasted. It works.
However, I don’t know how to query all options and suboptions under a module (e.g. coast) , for precisely controling the elements in the diagram. The website above isnot written in detail.
Any suggestions?

I usually use this page:

you can find detail information about each function.

grdimage, makecpt, grd2cpt, mat2grid are mostly used.

Thank you for your reply.
For example, colorbar module, where can I find the description of the set of parameters in the ‘frame ’option?

GMT.colorbar!(pos=(anchor=:BC,size=(12.5,0.3), horizontal=true, offset=(0,1.0),triangles=true),

refer to, you can find -B about frame


it’s in GMT style though. For example:

GMT.colobar(B = “af”)

i think there is little information about parameters in julia style.

I’m also looking for such information, hoping others can help.

I have tried to use the approach GMT.colobar(B = “af”) , this way can quickly convert code in GMT to julia, but I encounter problems when plotting a map in map. Maybe I’m missing some information.