IntelliJ IDEA Git plugin not authenticating

When I attempt to push from IntelliJ (via the Git plugin), the 1Password authentication prompt doesn't appear, and eventually the push fails with:

sign_and_send_pubkey: signing failed for ED25519 "SSH Key" from agent: communication with agent failed
git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.

When I open a terminal and authenticate IntelliJ manually, only then can I actually push anything. According to the 1Password ssh-agent docs, IntelliJ should work, but it's not.

OS: NixOS 24.11

IntelliJ version: IntelliJ IDEA 2024.3.2.2 (Ultimate Edition) Build #IU-243.23654.189

1Password version: 8.10.48

op version: 2.30.2

Command IntelliJ git plugin runs for pushing (I figured it might be useful because IntelliJ adds some options to it):

git -c credential.helper= -c core.quotepath=false -c log.showSignature=false push --progress --porcelain origin refs/heads/main:main