repositories {
    maven {
        name = "Modrinth"
        url = "https://api.modrinth.com/maven"
    }
}

dependencies {
    modImplementation "maven.modrinth:alexislib:${project.alexislibversion}"
}

For 26.1+ its just implementation. Then in gradle.properties add this and change what comes after accordingly

alexislibversion: 1.21.11-r1

Finally in fabric.mod.json add this

"depends": {
    "alexislib": "*"
  }

Thats it :)