Adding a label or annotation to a pcolormesh plot on mouse click

Hi! I have some code that is generating a pcolormesh plot, and “X” markers at specific coordinates. I would like to be able to click on a location on the plot and move the “X” marker and save the new/updated location. Below is my code so far (working environment: Windows 11, VS Code, .ipynb). It seems like there are a number of ways this could be done, and I am wondering if someone more well versed in the capabilities of matplotlib could suggest a good way to do this? Thanks!

import matplotlib.colors as colors
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
import polars as pl
import os

N = 734

def mouse_event(event):
    print('x: {} and y: {}'.format(event.xdata, event.ydata))

def echomap_plot_rectangular(d0, d1, x0, x1, save_to, labels, save=False):
        d0:734 by 170 numpy array of data 
        d1:734 by 170 numpy array of data 
        x0: 170 length 1d numpy array
        x1: 170 length 1d numpy array
        save_to: path to save echomap plots to
        labels: list of tuples of coordinates to label on the plot. x is radial, y is distance (0 to 50m).
    my_dpi = 96
    r0 = np.linspace(0,50,N)
    r1 = np.linspace(0,50,N)

    fig, (ax0, ax1) = plt.subplots(nrows=1, ncols=2, figsize=(2*(ECHOMAP_PIXELS/my_dpi), ECHOMAP_PIXELS/my_dpi), dpi=my_dpi)
    cid = fig.canvas.mpl_connect('button_press_event', mouse_event)

    # PLOT
    vm = int(np.maximum(np.max(d0), np.max(d1))) + 1

    im = ax0.pcolormesh(x0, r0, d0, vmin=0, vmax=vm)
    fig.colorbar(im, ax=ax0)
    ax0.set_title('plot xyz')

    im1 = ax1.pcolormesh(x1, r1, d1, vmin=0, vmax=vm)
    fig.colorbar(im1, ax=ax1)
    ax1.set_title('plot abc')
    # Unzip the coordinates into separate lists for x and y
    x_values, y_values = zip(*labels)
    y0 = y_values
    y1 = y_values

    # Add target markers to the existing plots
    ax0.scatter(x_values, y0, marker='x', color='black', s=250, linewidth=3)
    ax1.scatter(x_values, y1, marker='x', color='black', s=250, linewidth=3)  
    fig.suptitle(f'Echomaps') # adjust spacing between subplots so `ax1` title and `ax0` tick labels don't overlap

    if save:
        if not os.path.exists(save_to):
        fig.savefig(save_to + "xyz_echomaps.png")

%matplotlib qt

d0_sample = np.random.rand(N, 170)
d1_sample = np.random.rand(N, 170)
x0_sample = np.linspace(0, 170, 170)
x1_sample = np.linspace(0, 170, 170)
labels_sample = [(45, 15), (140, 22), (85, 40)]

echomap_plot_rectangular(d0_sample, d1_sample, x0_sample, x1_sample, save_to=".", labels=labels_sample)

Can you clarify a few things? you want to move one of the existing ‘X’ marks (click and drag) or click to add a new ‘X’?
2. when you say ‘save the new/updated location’ to you mean save the figure as an image immediately on click? Or just to be able to save after the change (can you just press the save button, or hit ‘s’ when the figure window is focused?)