Install abapgit and follow the links

From 2020

You have to install EUI library first

If you do not know the proxy parameters for ZABAPGIT_TEST_SSL

or you don’t have permission to add certificates in STRUST

or you cannot add parameters to /usr/sap/ED1/SYS/profile/DEFAULT.PFL

ssl/client_ciphersuites = 150:PFS:HIGH::EC_P256:EC_HIGH

ssl/ciphersuites = 135:PFS:HIGH::EC_P256:EC_HIGH

then download zip file

create offline project and import the zip file

Video instruction

Installing certificates is optional