If electoral register is created by the EMB, what type of technology used for collecting registration data?

NCSL, Online Voter Registration, 10/10/2018, accessed 16 February 2019

“As of October 10, 2018 a total of 37 states plus the District of Columbia offer online registration, and one other state (Oklahoma) has passed legislation and is currently phasing in implementation of their online registration. […]

Online voter registration systems supplement the traditional paper-based process, by which new voters fill out a paper form that is submitted to election officials, who confirm the registration is valid and enter the information from the paper application into the registration system.

Online voter registration follows essentially the same process, but instead of filling out a paper application, the voter fills out a form via an Internet site, and that paperless form is submitted electronically to election officials. In most states the application is reviewed electronically; if the request is confirmed to be valid, the new registration is added to the state’s voter registration list.

That validation step is done by comparing the information on the online registration form against the information provided by the same individual when he or she received a driver’s license or other state-issued identification card. The signature already on record with the state becomes the signature on record for voting. When the information does not match, the application is sent to officials for further review or action.”

United States of America, Mid-Term Congressional Elections 6 November 2018, ODIHR Limited Election Observation Mission [Final Report], accessed 16 February 2019

“Online registration was used in 37 states, while automatic registration was provided in 10 states.”

37 states in the US offer online registration services. The procedure is handled completely online. See sources for further details.