I cannot process live transaction on my website. Error log is as bellow. Thanks.

2022-01-10T01:45:53+00:00 DEBUG POST https://api.paypal.com/v1/oauth2/token?grant_type=client_credentials
Response Debug ID: 3a0421cc09c49
Response: Array
(
    [code] => 200
    [message] => OK
)


2022-01-10T01:45:53+00:00 DEBUG POST https://api.paypal.com/v1/billing-agreements/agreement-tokens
Request Body: {"description":"Checking if reference transactions are enabled","payer":{"payment_method":"PAYPAL"},"plan":{"type":"MERCHANT_INITIATED_BILLING","merchant_preferences":{"return_url":"https:\/\/example.com\/return","cancel_url":"https:\/\/example.com\/cancel","skip_shipping_address":true}}}
Response Debug ID: e1bf6c398bd95
Response: Array
(
    [code] => 403
    [message] => Forbidden
)

Response Body: {"name":"AUTHORIZATION_ERROR","debug_id":"e1bf6c398bd95","message":"Authorization error","information_link":"https://developer.paypal.com/webapps/developer/docs/api/#AUTHORIZATION_ERROR","details":[{"name":"REFUSED_MARK_REF_TXN_NOT_ENABLED","message":"This merchant account is not permitted to create Merchant Initiated Billing Agreement"}]}

2022-01-10T02:49:28+00:00 DEBUG POST https://api.paypal.com/v1/oauth2/token?grant_type=client_credentials
Response Debug ID: 898a3d3ff030f
Response: Array
(
    [code] => 200
    [message] => OK
)


2022-01-10T02:49:29+00:00 DEBUG POST https://api.paypal.com/v1/billing-agreements/agreement-tokens
Request Body: {"description":"Checking if reference transactions are enabled","payer":{"payment_method":"PAYPAL"},"plan":{"type":"MERCHANT_INITIATED_BILLING","merchant_preferences":{"return_url":"https:\/\/example.com\/return","cancel_url":"https:\/\/example.com\/cancel","skip_shipping_address":true}}}
Response Debug ID: 44c7154bb5e67
Response: Array
(
    [code] => 403
    [message] => Forbidden
)

Response Body: {"name":"AUTHORIZATION_ERROR","debug_id":"44c7154bb5e67","message":"Authorization error","information_link":"https://developer.paypal.com/webapps/developer/docs/api/#AUTHORIZATION_ERROR","details":[{"name":"REFUSED_MARK_REF_TXN_NOT_ENABLED","message":"This merchant account is not permitted to create Merchant Initiated Billing Agreement"}]}