Add MIME-types to Nextcloud

vi /var/www/nextcloud/config/mimetypemapping.json
{
    "eml": ["message/rfc822"],
    "dcm": ["application/dicom"],
    "flac": ["audio/flac"],
    "m3u": ["audio/mpegurl", "text/plain"],
    "m3u8": ["audio/mpegurl", "text/plain"],
    "m4a": ["audio/mp4"],
    "m4b": ["audio/mp4"],
    "mp3": ["audio/mpeg"],
    "ogg": ["audio/ogg"],
    "opus": ["audio/ogg"],
    "pls": ["audio/x-scpls", "text/plain"],
    "wav": ["audio/wav"]
}

Update tables

php occ maintenance:mimetype:update-db --repair-filecache
php occ maintenance:mimetype:update-js