You can resubmit multiple drafts. Your teacher may have you submit your final draft in a separate assignment (recommended). You would follow the same steps to submit a final draft as you do for a rough draft.
If the teacher has made similarity results visible, then a student can view plagiarism report for his/her submissions (it might take a minute or so to generate the report).
Open Unicheck report and click Generate report. Wait few seconds or so and when same button changes to Download report, click it to download the report.