To make use of Pehkui in your own mod, you'll first need to go to the repositories
block of your build.gradle, typically found right before the dependencies block,
and add the JitPack Maven to the bottom of the block like below:

// ...

repositories {
	// ... your other Maven repositories above, if any ...
	maven {
		url = "https://jitpack.io"
	}
}

dependencies {
	// ...
}

// ...

Now that a Maven repository is specified, add pehkui_version=x.y.z-w to your
gradle.properties, replacing x.y.z-w with one of the available version strings from
the list of release tags.

Lastly, in your build.gradle's dependencies block, add the corresponding line from
below depending on your mod loader:

modApi("com.github.Virtuoel:Pehkui:${pehkui_version}", {
	exclude group: "net.fabricmc.fabric-api"
})

implementation "com.github.Virtuoel:Pehkui:${pehkui_version}"

implementation fg.deobf("com.github.Virtuoel:Pehkui:${pehkui_version}")

modApi("com.github.Virtuoel:Pehkui:${pehkui_version}")

If you're using Forge with ForgeGradle, make sure the mixingradle plugin is present and
applied:

Make sure the following line is present in your build.gradle's
buildscript { repositories {} } block.

maven { url = "https://repo.spongepowered.org/repository/maven-public/" }

Then make sure the following line is present in your build.gradle's
buildscript { dependencies {} } block.

classpath "org.spongepowered:mixingradle:0.7-SNAPSHOT"

Next, make sure the following line is present in your build.gradle.

apply plugin: "org.spongepowered.mixin"

Then regenerate your run configurations with genEclipseRuns, genIntellijRuns, or
genVSCodeRuns depending on your IDE.

If you're using Forge with ForgeGradle 4 or older, make sure refmap remapping is enabled
in your build.gradle's run configuration blocks.

Make sure the following lines are present in the client {}, server {}, and data {}
run configuration blocks.

property 'mixin.env.remapRefMap', 'true'
property 'mixin.env.refMapRemappingFile', "${projectDir}/build/createSrgToMcp/output.srg"

Then regenerate your run configurations with genEclipseRuns, genIntellijRuns, or
genVSCodeRuns depending on your IDE.