Please add support for [https:Can't pass argument to parameter that is type=file (<input name="file" type="file" jsonaware="true">) In the "$JENKINS/job/wiki.jenkins.io$JOB/display/build" page such type is represented as button
!image-2019-08-22-04-39-36-009.png!
In the "$JENKINS/Parameter+Separator+Plugin.] It's rendered really ugly when using .job/$JOB/parambuild" page is it represented as text input, but the biggest problem is that parameter value from URL is not passed to this field at all