The company says shopping on smartphones and tablets now accounts for more than 70% of all its online sales.
Figures found total sales in Scotland were down 18.6% last month, compared against 1.9% in June 2019.
Job losses are expected across its head office in Glasgow and distribution centre in Bellshill.
Figures for last month show a decrease of 40.3% compared with April 2019 amid the coronavirus pandemic.
The National Union of Students is calling for greater support for students who have lost part-time jobs.
Total sales in the country decreased by 13% on March 2019, according to the Scottish Retail Sales Monitor.
The Scottish Government said the coronavirus outbreak is an 'economic emergency'.