Adding images in LaTex documents is difficult ion android because of difficulty in locating the folder in which .tex document is stored. This video answers this problem. This video shows how to locate folder in which tex documnet stored and discuss adding image in vertex free version , verbtex pro version and overleaf.
Remember to use
\usepackage{graphicx} in preamble.
and locate folder in which document is stored and save image in that folder.
\invludegraphics[scale= 1]{imagename}
instes of scale , width can also be used with \pagewidth or \linewidth options.
figure environment can be used to have caption and label and to include figure in table of figures.