Right-click and make shortcut in web browser:
javascript:(async () => {await navigator.clipboard.writeText(document.querySelector('ytd-engagement-panel-section-list-renderer > #content > ytd-transcript-renderer > #content > ytd-transcript-search-panel-renderer > #body > ytd-transcript-segment-list-renderer > #segments-container').innerText);)();
javascript:(async()=>{let e=document.querySelector('ytd-engagement-panel-section-list-renderer > #content > ytd-transcript-renderer > #content > ytd-transcript-search-panel-renderer > #body > ytd-transcript-segment-list-renderer > #segments-container');if(e){let t=e.innerText;await navigator.clipboard.writeText(t);let a=new Blob([t],{type:'text/plain'}),n=document.createElement('a');n.href=URL.createObjectURL(a),n.download='youtube_transcript.txt',document.body.appendChild(n),n.click(),document.body.removeChild(n)}else alert('Transcript not found. Please open the transcript panel first.')})();