I am trying to use the /data/symbology convert API to map securities. When I tried to convert to other symbol systems I found that the fields of 'SEDOL', 'CUSIP', and 'ISIN' showing as 'access to field(s) denied'.
Is that something at the product level or it is something related with my entitlement and access?
It certainly does appear that this may be related to your entitlement and access. To confirm, I would first log in to the Elektron Data Platform playground, then navigate to the /data/symbology endpoint once you are in there.
First, try a simple example with the symbol/instrument of your choice - it defaults to IBM.N. Assuming you get data back, you should see all the conversion results in a table. For example:
I've highlighted a couple of columns that I can access. From here, you can simply request for a list of conversions. For example:
I've requested for 'CUSIP', 'ISIN' and 'SEDOL'.