I am having the same problem on Ventura with Xcode 14.1.
I tried the command listed by Quinn, but codesign just reports a usage message instead.
I added a colon which apparently is deprecated, but it does produce some output (I am using the path to extension stored in the container app as built by Xcode).
I see com.apple.security.get-task-allow. What can I do to get debugging to work?
% codesign -d -v --entitlements :- (path to extension inside container app)
Format=bundle with Mach-O thin (arm64)
CodeDirectory v=20500 size=93466 flags=0x10000(runtime) hashes=2909+7 location=embedded
Signature size=4790
Signed Time=Nov 27, 2022 at 5:30:25 PM
Info.plist entries=24
Runtime Version=13.0.0
Sealed Resources version=2 rules=13 files=401
Internal requirements count=1 size=208
Warning: Specifying ':' in the path is deprecated and will not work in a future release
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "https://www.apple.com/DTDs/PropertyList-1.0.dtd"><plist version="1.0"><dict><key>com.apple.security.app-sandbox</key><true/><key>com.apple.security.application-groups</key><array><string>6MR872QP3J.group.com.gentlemencoders.RAWPower</string></array><key>com.apple.security.files.user-selected.read-write</key><true/><key>com.apple.security.get-task-allow</key><true/><key>com.apple.security.network.client</key><true/></dict></plist>