best bicycle lock for teen

[iwantavuvezela]

looking for a lightish lock for DD to lock up bike at school. (and lightish enough to carry) possibly a number lock so no faff with keys.

we have a solid metal lock for more public areas

TIA

Which one did you get in the end @iwantavuvezela?

I got this one off Amazon which has worked well (lighter and seems sturdier enough for school etc)

www.amazon.co.uk/gp/product/B09NX4S2R4/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&th=1

ideally youneed a frame lock like this
and the corresponding chain or a separate chain lock.