You’ll need SFDX with a configured dev hub. Since you’ll use Quantic to assemble LWCs, and LWCs are meant to be managed in SFDX projects, you’ll need SFDX.
In addition, while it’s not strictly necessary, we recommend installing and configuring the Coveo for Salesforce package, since it can automatically take care of important steps at the search token authentication stage (see the first two steps of the Getting Started with Coveo for Salesforce Guide).