How can I put the envelope icon on the Acrobat toolbar on the left

Hello,

I use Adobe Acrobat DC Pro (32 bits) but the envelope icon on the Acrobat toolbar is on the left (see screenshot below)

It would be easier if I have the envelope icon on the left. On my previous version, the icon was on the left. When I want to customize the quick toolbar, I did not find the envelope icon.

Do you have a solution ?

Many thanks for your help.

Olivier