mkcert makes it easy to serve local content (i.e., localhost) over HTTPS. By default, however, Node-based servers (e.g., Express) won't accept mkcert's certificates; so you have to set this environment variable:
export NODE_EXTRA_CA_CERTS="$(mkcert -CAROOT)/rootCA.pem"Source: https://github.com/FiloSottile/mkcert?tab=readme-ov-file#using-the-root-with-nodejs