systools.httpgetclob vs qsys2.http_post

can someone tell me why when I use the qsys2.http_post below (uncomment out
the qsys2.http_post and header parm) it will not work... but works fine
with systools.httpgetclob?



select *
from json_table(
-- qsys2.http_post('
https://api.mapbox.com/geocoding/v5/mapbox.places/Mobile' concat
systools.httpgetclob('
https://api.mapbox.com/geocoding/v5/mapbox.places/Mobile' concat
'.json?access_token='
concat
'myKey' concat
'&limit=1'

,cast(null as clob(1k))
--
,'{"header":"content-type,application/x-www-form-urlencode","sslTolerate":"true"}'
)
,'$' columns (
Lat float path '$.features[0].center[1]'
,Lon FLOAT path '$.features[0].center[0]'
,PName CHAR(100) path '$.features[0].place_name'
) error on error
) as x;