print_grid=True
in fig = make_subplots() to see the axes name assigned to each subplot.
Then to add an annotation to the subplot referenced with respect to ‘x2’, ‘y2’, specify the corresponding axes as follows:
xref ='x2',
yref ='y2'
See help(go.layout.Annotation.xref):
Help on property:
Sets the annotation's x coordinate axis. If set to an x axis id
(e.g. "x" or "x2"), the `x` position refers to an x coordinate
If set to "paper", the `x` position refers to the distance from
the left side of the plotting area in normalized coordinates
where 0 (1) corresponds to the left (right) side.
The 'xref' property is an enumeration that may be specified as:
- One of the following enumeration values:
['paper']
- A string that matches one of the following regular expressions:
['^x([2-9]|[1-9][0-9]+)?$']
Returns
-------
Any