Get milestone, plan, run detailed statuses to google spreadsheet. Combine with JiraReportingInGSheets to get magnificent reports!
Use custom functions to get data via TestRail api, combine with sheet formulas and build graphs.
Make reports from templates with 'Generate TestRail Report TEMPLATE' option in Add-on menu, update it with your milestone, plan, run IDs from TestRail to start the report up.
Type in =tr to get the drop-down menu with the list of functions available for use.
E.g. use trRunStatus(RunID) function to get the available statuses vs count of test cases and use trRunDefects(RunID) to get defect keys linked to TCs.
Watch the video guide and visit out website for more details.
Best combined with JiraReportingInGSheets add-on reports.