Install Contao 4.9 or 4.12 on server with php 7.4

Hi everyone,

I need ton install Contao 4.9 or 4.12 on a server with php 7.4. I can't upgrade the server for now. But contao-manger only proposes Contao 4.13 or 5.3. How can I install Contao 12 ?

Thanks.