Lightdash supports metrics written in both the dbt Semantic Layer syntax, or in the Lightdash metrics syntax. You can learn more about the different ways of adding metrics to Lightdash here.
To have dbt Semantic Layer enabled on your Lightdash instance, you'll need:
To be using a paid version of dbt (i.e. dbt Cloud - Semantic Layer is not available to self-hosted dbt users).
To be using Lightdash Cloud (dbt Semantic Layer is not available for Self-Hosted users)
Your dbt cloud environment ID for the environment that holds your semantic layer
A dbt cloud API token with read access to the semantic layer
You'll need to share the secrets from (3) & (4) with the Lightdash team in something like 1password secrets or https://onetimesecret.com.
Once you have all of that ready, you can message the Lightdash team (either in Slack or in the Lightdash app) to get you started.