Upload your own logo to your server... Then edit the blade files to use your logo files instead of the pre-defined / default ones.
Original Logo (example)
<img src="{{ public_asset('/assets/img/logo_blue.svg') }}" class="rounded img-mh50">
Your Logo (example)
<img src="{{ public_asset('/myfolder/myanotherfolder/mylogo.jpg') }}" class="rounded img-mh50">
or
<img src="{{ public_asset('/myfolder/mylogo_big.png') }}" class="rounded img-mh100">
Commonly, editing app.blade.php of your theme would be enough to apply your logo to all other blades. ( This depends on the theme you use, default / disposable / stisla uses the same logic but others may be different )