It might be easier to get ESP01 based logger to output data to p tags and use innerHTML to get values.

The javascript on this page could be moved into .js file , included from else where.

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Data

values

min/max min, max , range in data

labels

Graphs - using canvas -

This page uses the canvas and minimal JavaScript to draw graphs. The width is adjusted to the numberof data points. Adjust JavaScript to suit.

Place the graph in the centre of the window, and consider margin | border | padding. The grid should not dominate.