Confused can anyone help explain SMP to me-pretty please?!

[Natnat29]

Hi, any help muchly appreciated, cannot get my head around mat pay at all and the person at work who would normally explain is on mat leave.

basically im 24 weeks and will be putting in my maternity pay form and MATB1 form this week to HR dept- my question is do they sort out the Statutory mat pay? or do i need to get in touch will someone to request this outside of work?
Also will i get the basic £107 a week or is it based on my earnings?
thanks for any help- ive read my mat quide and the online gov guide but its not going in for some reason
Natnat :)

They will sort it out for you.
You will get 6 weeks at 90% of full salary, and then 33 weeks at £135.45 (or 90% of your average gross weekly earnings, if that is less than £135.45).
Then you're entitled to a further 13 weeks unpaid leave.