[exim] How to make proxy support work in exim

Hi
Nginx and Exim on the same host, Nginx runs as a smtp proxy for exim.
Nginx v1.22.0 config fragment:

```
mail {
...

  server {
    listen    25;
    protocol  smtp;
    proxy_protocol on;
    smtp_auth none;
    starttls on;
  }
...
}
```
(Exim v4.96, compiled with SUPPORT_PROXY). Exim config:

```
hostlist hosts_proxy = <; 127.0.0.1; 192.46.111.11
```

But PROXY protocol seems to be not recognised by exim, Exim logs:

```
SMTP syntax error in "PROXY TCP4 209.85.128.171 192.46.111.11 43960 25"
H=localhost [127.0.0.1] unrecognized command
```

How to make proxy support work in exim?
Thank you