1. Use POST method.
2. Set the end point.
Sandbox – https://test.salesforce.com/services/Soap/u/35.0
Production – https://login.salesforce.com/services/Soap/u/35.0
Use custom domain URL if my domain is enabled and prevent login from test or login.salesforce.com is enabled.
3. Set your headers as below.
SOAPAction = “”
Content-Type = text/xml
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4. Use the following as body.
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:urn="urn:partner.soap.sforce.com">
<soapenv:Body>
<urn:login>
<urn:username>Login ID</urn:username>
<urn:password>Password</urn:password>
</urn:login>
</soapenv:Body>
</soapenv:Envelope>
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5. Get the SessionId.
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