This pack is intended to be used alongside the Classic Textures texture pack (aka Programmer Art), as the default lava texture in the Classic Textures pack is significantly older than the one used in Java's Programmer Art. This pack ignores the lava texture for Classic Textures and just uses the default one instead (which is the same as Java's texture).
Java Lava is a free Minecraft Bedrock texture pack. Downloaded 2,000 times. Download it and open it directly in the game.