Unable to use Conditional BuildStep Plugin with Testlink Plugin

Testlink Plugin does not appear as a build step.

Need to be able to optional run automated tests using Testlink plugin based on a parameter defined at run time

Is this the cause of the issue?
If you're not able to add the builder of your choice within a conditional build step (because it's not available within the dropdown), then this is likely because the builder does not provide a @DataBoundConstructor constructor and/or the Descriptor does not extend hudson.tasks.BuildStepDescriptor. For non programmers: the plugin you would like to use does not yet follow the newest Jenkins coding guidelines