i’m not 100% sure but it should look like the normal check output as described here: Local checks (look for multiple values)
count1=42|count2=21;23;27|count3=73
so it should be something like (untested):
SELECT '0', SUM(highly_vulnerable_count), CONCAT('| highvulncount=',SUM(highly_vulnerable_count),'|secondvalue=',SUM(secondCount)) from public.bopatchreports