Before moving ahead, make sure you have OTA Provider is commissioned and running.
After commissioning is successful, announce OTA provider's presence using chip-tool. On receiving this command OTA requestor will query for OTA image.
./out/debug/chip-tool otasoftwareupdaterequestor announce-ota-provider <PROVIDER NODE ID> 0 0 0 <REQUESTOR NODE ID> 0
Once the transfer is complete, OTA requestor sends ApplyUpdateRequest command to OTA provider for applying the image. Device will restart on successful application of OTA image.
./out/debug/chip-ota-provider-app -f hello-world.bin
./out/debug/chip-tool pairing onnetwork 12345 20202021