Docker xcaddy with custom plugins

Hello!

I’m trying to build a custom Caddy as a docker container but I run in to the following issue:

[+] Building 0.2s (2/2) FINISHED
 => [internal] load local bake definitions                                                                                                                                                                  0.0s
 => => reading from stdin 561B                                                                                                                                                                              0.0s
 => [internal] load build definition from Dockerfile                                                                                                                                                        0.0s
 => => transferring dockerfile: 386B                                                                                                                                                                        0.0s
Dockerfile:7

--------------------

   5 |         xcaddy build \

   6 |          --with github.com/mholt/caddy-l4

   7 | >>>      --with github.com/hslatman/caddy-crowdsec-bouncer

   8 |          --with github.com/caddy-dns/desec

   9 |

--------------------

failed to solve: dockerfile parse error on line 7: unknown instruction: --with

I use the example from the instructions

FROM caddy:builder-alpine AS builder

RUN --mount=type=cache,target=/go/pkg/mod --mount=type=cache,target=/root/.cache/go-build xcaddy build --with github.com/mholt/caddy-l4--with github.com/hslatman/caddy-crowdsec-bouncer--with github.com/caddy-dns/desec

FROM caddy:alpine

COPY --from=builder /usr/bin/caddy /usr/bin/caddy

What am I doing wrong?