Try adding HTTP Cookie Manager to your Test Plan, if the "session" is being handled by cookies - the Cookie Manager will automatically resolve it.
If not - then most probably you will need to perform correlation - the process of detecting dynamic element(s), extracting them into JMeter Variable(s) using a suitable JMeter PostProcessor and replacing recorded hard-coded value in the next request with the JMeter Variable.
Example test plan outline:
- Request 1
- Post Processor to extract token from the Request 1 into variable
token
- Request 2 sending
${token}
from the request 1 as a parameter
You can consider an alternative way of recording a JMeter test using cloud-based proxy service, it is capable of exporting recorded scripts in "SmartJMX" format which automatically detects and handles dynamic parameters. See How to Cut Your JMeter Scripting Time by 80% article for more details.