HELP S.O.S. MAYDAY MAYDAY!! I cannot figure out how to use Gradle

[LEOcab]

First and foremost, I don't know whoever had the grand master idea to switch from Maven to Gradle but I hope you have a very, very merry Christmas.

Anyway, I've run a lightly customized build of Essentials for many years. It literally just injects some code into the /sethome command to communicate with another plugin. Now I want to update it and can't.

I originally came here to ask how to get rid of the dumb checkStyles thing but I figured that out. What I can't figure out now is how to import a local JAR dependency to the project. In maven it was just <dependency><scope>system</scope></dependency> but Gradle doesn't like anything I throw at it. As far as my googling skills go, this SHOULD work:

dependencies {
    implementation files('./MyPlugin.jar')
}

and yet it doesn't. Yes I copied the jar to the same folder as build.gradle, still not working. Tried both forward slashes and double back slashes for paths. It throws this error:

* Where:
Build file 'C:\Users\Leo\Desktop\Essentials-2.x\build.gradle' line: 17

* What went wrong:
A problem occurred evaluating root project 'EssentialsXParent'.
> Could not find method implementation() for arguments [file collection] on object of type org.gradle.api.internal.artifacts.dsl.dependencies.DefaultDependencyHandler.

Thanks in advance for any tips

[LEOcab]

For the love of god somebody help me... am I really the only caveman motherfudger that's still just using local dependencies? I don't like repos just let me link my jar file bro