gt;</span> <span class="tsd-signature-type">Promise</span><span class="tsd-signature-symbol">&lt;</span><span class="tsd-signature-type">string</span><span class="tsd-signature-symbol">&gt;</span></div><aside class="tsd-sources"><ul><li>Defined in configuration.ts:20</li></ul></aside></section><section class="tsd-panel tsd-member"><a id="apikey" class="tsd-anchor"></a><h3 class="tsd-anchor-link"><code class="tsd-tag">Optional</code><span>api<wbr/>Key</span><a href="#apikey" aria-label="Permalink" class="tsd