When following the (US) pattern, I substituted the dc for a hdc, and increased 2 stitches at the beginning and end of each row, instead of 3 stitches.

Used white colour, which is 5ply yarn.

Dimension 1 was 42cm, ending with 83 hdc.

Dimension 2 was 28 rows of 83 hdc, measuring 21cm.

Used 80g of white yarn.

For the chains I followed this YouTube video
https://youtu.be/uLE6N-RIvB4