These Regulations amend regulation 3 (universal credit - standard allowance modification) of the Social Security (Coronavirus) (Further Measures) Regulations 2020 (S.I. 2020/371). By virtue of that amendment the modified rates specified in that regulation are to take effect in relation to each award of universal credit in the first assessment period that ends on or after 6th April 2020.
Local copy of SI

https://beta.parliament.uk/statutory-instruments/9gnHkrIp