No.
Read the YouTube T&Cs:
5.1 A) You agree not to distribute any part of or parts of the Website or the Service, including but not limited to any Content, in any medium without YouTube's prior written authorisation, unless YouTube makes available the means for such distribution through functionality offered by the Service (such as the YouTube Player);
5.1 B) You agree not to alter or modify any part of the Website or any of the Service (including but not limited to the YouTube Player and its related technologies);
5.1 C) You agree not to access Content through any technology or means other than the video playback pages of the Website itself, the YouTube Player, or such other means as YouTube may explicitly designate for this purpose;
5.1 D) You agree not to (or attempt to) circumvent, disable or otherwise interfere with any security related features of the Service or features that (i) prevent or restrict use or copying of Content or (ii) enforce limitations on use of the Service or the content accessible via the Service;
https://www.youtube.com/static?gl=GB&template=terms[
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This means that Youtube downloading is against the terms and conditions, and should be considered infringing copyright. And that's not something we approve of here.