To use Double-Opt-In, a redis version greater or equal to 3.0 has to be installed.
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1.) An applicant creates a new profile in the applicant portal
2.) This applicant data is saved for 24 hours in the redis database
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4.) Through the Double-Opt-In link and the token, the applicant is forwarded to the registration page, where is his name and email have already been filled out. Afterwards, the registration process takes place as usual.
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