While the repository has 399074e to update the minimum LXD version to 3.0, but the conjure-up doc site still has 2.18 as the minimum version.
$ curl -s https://docs.conjure-up.io/devel/en/ | grep 2.18
<p><strong>conjure-up</strong> requires that the minimum version of LXD be <strong>2.18</strong>. Additionally,
While the repository has 399074e to update the minimum LXD version to 3.0, but the conjure-up doc site still has 2.18 as the minimum version.
Looks like the devel branch has some lags from master: https://github.com/canonical-docs/conjure-up-docs/compare/devel...master