How to plot Gann fan in any stock charts

A Gann Fan is a technical analysis tool developed by W.D. Gann in the early 20th century. It consists of a series of diagonal lines (called Gann angles) emanating from a significant high or low point on a price chart. These lines represent different ratios of price movement to time (e.g., 1x1 for a 45-degree angle, where price changes by 1 unit per 1 unit of time). The tool helps identify potential support and resistance levels, trend strength, and reversal points by assuming markets move in geometric and cyclical patterns.
Common angles include:

1x8 (shallow, ~82.5°)
1x4 (~75°)
1x3 (~71.25°)
1x2 (~63.75°)
1x1 (45° – the key "trendline")
2x1 (~26.25°)
3x1 (~18.75°)
4x1 (~15°)
8x1 (steep, ~7.5°)

In an uptrend, prices above the 1x1 line are bullish; below it, bearish. The fan is most effective on linear-scaled charts where time and price units are equidistant.