Can I exclude my own thesis submission on Turnitin repository saved by mistake?
No. As far as I am aware there isn't. The person reviewing your thesis after submission can exclude the earlier submission though. You should probably make whoever is checking this aware.
You should however, be aware that submitting your thesis to a user account provided by someone else at a different university may be breaking some rules, or at least expectations - either at your university, at your friends university or turnitin's rules (possibly all three). This is not a serious infraction, and I wouldn't expect any comeback other than disapproving tuts, but its still bad practice.
Students often want to submit their work to check the turnitin score to see if they have paraphrased things sufficiently not to trigger the plagiarism checks. This betrays a misunderstanding of what plagiarism is. Taking text from another source and paraphrasing it, even with attribution, is still on the &quot;plagiarism spectrum&quot;.