Yes, it is possible using POST request see please example on https://tcs.ext.here.com/examples/v3.1/rme_basic
Like this bash cUrl request:
curl
'https://fleet.api.here.com/v8/match/routelinks?mode=fastest;car;traffic:disabled&routeMatch=1&apiKey=***'
\ -H 'Connection: keep-alive' \ -H 'Pragma: no-cache' \ -H
'Cache-Control: no-cache' \ -H 'Accept: application/json,
text/javascript, /; q=0.01' \ --data-raw
$'LATITUDE,LONGITUDE\n53.3737131,-1.4704939\n53.3742428,-1.4677477\n53.3745646,-1.467576\n53.3758092,-1.4665675\n53.3765066,-1.4645076\n53.3750689,-1.4637029\n53.3745968,-1.4630377'
\ --compressed
You tried to utilized GET request but there is limitation on length of string of URL.