Hello NICOLASOLIUY,
Please try the following steps in the web gui of 1950 switch (in the example the DHCP server is 10.1.11 please change it accordingly):
Perform the following tasks:
− Enable the DHCP service.
− Configure VLAN-interface 10 to operate in DHCP relay agent mode.
− Specify the IP address of the DHCP server as 10.1.1.1.
Access the advanced settings page to perform the following tasks:
− Enable the DHCP relay agent to record client information.
− Enable the relay agent to fresh relay entries periodically.
− Set the refresh internal to 100 seconds.
If you are setting it up using command line you may use the following link to see how it is configured in CLI:
https://support.hpe.com/hpesc/public/docDisplay?docId=c03477763&docLocale=en_US
Hope this helps!