Параметры запроса REGISTER:
{"signature":"ZTM5ODFjOWYwNmQ5NGRlZjYzYTMzYjc1ZTZjZjM1NTE=","amount":100,"currency":643,"reference":"9353fe2f-9ed0-4fae-81ef-dcf556c865f7","description":"test","sector":7964,"url":"https:\/\/api.mosgorpass.ru\/v8.2\/payment\/callback\/b2p\/success","fail_url":"https:\/\/api.mosgorpass.ru\/v8.2\/payment\/callback\/b2p\/failure","client_ref":"96f74d62-02ff-11eb-a411-0242afd3047f","email":"pavel.semenov111@gmail.com","fiscal_positions":"1;100;6;test"}

Ответ:
<?xml version="1.0" encoding="UTF-8"?><order>
<id>337856603</id>
<state>REGISTERED</state>
<inprogress>0</inprogress>
<date>2021.10.19 12:46:11</date>
<amount>100</amount>
<currency>643</currency>
<email>pavel.semenov111@gmail.com</email>
<reference>9353fe2f-9ed0-4fae-81ef-dcf556c865f7</reference>
<description>test</description>
<url>https://api.mosgorpass.ru/v8.2/payment/callback/b2p/success</url>
<parameters number="5">
<parameter>
<name>amount_actual</name>
<value>100</value>
</parameter>
<parameter>
<name>client_ref</name>
<value>96f74d62-02ff-11eb-a411-0242afd3047f</value>
</parameter>
<parameter>
<name>fail_url</name>
<value>https://api.mosgorpass.ru/v8.2/payment/callback/b2p/failure</value>
</parameter>
<parameter>
<name>paypage_open_count</name>
<value>0</value>
</parameter>
<parameter>
<name>payments_executed</name>
<value>0</value>
</parameter>
</parameters>
<signature>N2RiZThiOWI2NWY3ZTRlYTVhMzZiYmI3MmY1M2ZhODU=</signature>
</order>

Параметры запроса AUTHORIZE_BY_TOKEN:
{"signature":"OTJkZTc4ZmUxOWQzYmM3OGZmN2MyYWQ2ZTI4MGM5ZjU=","id":"337856603","token":"1ec5421e-ff18-4cfa-acfa-c3bb0c11d058","sector":7964}

Ответ:
<?xml version="1.0" encoding="UTF-8"?><operation>
<order_id>337856603</order_id>
<order_state>REGISTERED</order_state>
<reference>9353fe2f-9ed0-4fae-81ef-dcf556c865f7</reference>
<id>470714712</id>
<date>2021.10.19 12:46:12</date>
<type>AUTHORIZE_BY_TOKEN</type>
<state>REJECTED</state>
<reason_code>4</reason_code>
<message>Transaction declined by Issuer</message>
<pan>426102******7732</pan>
<email>pavel.semenov111@gmail.com</email>
<amount>100</amount>
<currency>643</currency>
<signature>MGU2MTRiMjNhNmEwOGU5ZGFhNDcwZjZlYWJjYzRhY2E=</signature>
</operation>