I have rephrased my post, plus adding lines of codes:
Assuming a graph with 4 lines, coded using the feature traces.append(), I would like to know if it is possible to add a shape on the y axis, a straight horizontal line, but for each of the four lines.
Basically, It would be a straight line on the “trace” part, not on the layout.
What I am looking to do it’s plotting the minimum of each line. So I would end up having 8 lines, 4 with my time series, and 4 horizontal lines with the minimum of each of the time series.