Transaction

[Error Code: 1101] error caused by: 1 error occurred:
	* transaction execute failed: [Error Code: 1101] cadence runtime error: Execution failed:
error: unexpectedly found nil while forcing an Optional value
 --> 7cd83cc647fadac5edfdbd5b75aab6a09473838550a833a183aaf1f855a87bdb:9:28
  |
9 |         let payerVaultRef = signer.capabilities.borrow<auth(FungibleToken.Withdraw) &FlowToken.Vault>(/public/flowTokenReceiver)!
  |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^