Error HTTPError: 403 Client Error: Forbidden for url: https://api.semanticscholar.org/graph/v1/paper/search?query=

Response Content: {"message":"Forbidden"} INFO:backoff:Backing off search_for_papers(...) for 201.4s (requests.exceptions.HTTPError: 403 Client Error: Forbidden for url: https://api.semanticscholar.org/graph/v1/paper/search?query=patient-specific+network+survival+prediction+multi-omics+graph+neural+network+transformer&limit=10&fields=title%2Cauthors%2Cvenue%2Cyear%2Cabstract%2CcitationCount) Backing off 201.4 seconds after 11 tries calling function search_for_papers at 14:19:00 Response Status Code: 403 Response Content: {"message":"Forbidden"} INFO:backoff:Backing off search_for_papers(...) for 543.2s (requests.exceptions.HTTPError: 403 Client Error: Forbidden for url: https://api.semanticscholar.org/graph/v1/paper/search?query=patient-specific+network+survival+prediction+multi-omics+graph+neural+network+transformer&limit=10&fields=title%2Cauthors%2Cvenue%2Cyear%2Cabstract%2CcitationCount) Backing off 543.2 seconds after 12 tries calling function search_for_papers at 14:22:22 Response Status Code: 403 Response Content: {"message":"Forbidden"} INFO:backoff:Backing off search_for_papers(...) for 1480.3s (requests.exceptions.HTTPError: 403 Client Error: Forbidden for url: https://api.semanticscholar.org/graph/v1/paper/search?query=patient-specific+network+survival+prediction+multi-omics+graph+neural+network+transformer&limit=10&fields=title%2Cauthors%2Cvenue%2Cyear%2Cabstract%2CcitationCount) Backing off 1480.3 seconds after 13 tries calling function search_for_papers at 14:31:26

I have already added open-api-key and S2_API_KEY value as environment by using shell scrtip export xxx in linux server,but the error still came out.

Do I have to use the S2_API_KEY in the program ? Coud I just use openai key api?

Thanks in advance!