In customize → site title
you can upload a svg here:
Screenshot 2023-09-04 at 11.18.39.png
if wordpress doesn't allow you to upload a svg, you could install a plugin like https://wordpress.org/plugins/svg-support/
you could also use type "html" here, and enter the text of the svg:
you can find the svg as text when you open your svg file with a texteditor
Screenshot 2023-09-04 at 11.19.49.png