Emis Web API GetMedicationIssues on PatientAcessEMISWEBV4_3

I am calling getMedicationIssues web api and it has a parameter patientId which is integer type the value I have assigned it is 9999999999 which is too large to be shored in integer type and long type is not acceptable. So, how to pass this argument?

patientId in EMIS Web is a locally assigned integer, scoped to a single EMIS Web database.

I guess that 9999999999 is a dummy NHS Number?

It may be worthwhile picking up a valid dummy NHS number rather than 9999999999 as the last digit is a checksum that should be trapped.
There are some dummy NHS numbers here : Dummy NHS numbers - Discovery Data Service

Not sure why long isn’t acceptable? However I have seen it as text from some systems for formatting purposes to aid easier reading / data entry e.g. 123-456-7890, or 123 456 7890.
I frequently receive NHS numbers as text but I would never request them as such!

Apologies I have no knowledge of the API can only speak of my experience with NHS numbers.

As above.

We use GetMatchedPatient API to find the patient first and use the EMIS ID in the response from that call in subsequent calls.