Hi vinamrasinghal151,
I would like to ask you if you already did this implementation? I believe that you can avoid use the TPAM website by using it´s DLL implementation. With this, you can simply add in your BP script the DLL and use a C# code to get the credential.
I believe that you will need a second bot like John said just to retrieve that credential, so one credential will be necessary just to go to TPAM and retrieve this second one (with more access, I believe).
Could you post here your achievement on this?