Problems installing LHPADF6

I am trying to install LHPADF6 and I get the following error:

curl: (60) SSL certificate problem: Invalid certificate chain
More details here: https://curl.haxx.se/docs/sslcerts.html

curl performs SSL certificate verification by default, using a "bundle"
 of Certificate Authority (CA) public keys (CA certs). If the default
 bundle file isn't adequate, you can specify an alternate file
 using the --cacert option.
If this HTTPS server uses a certificate signed by a CA represented in
 the bundle, the certificate verification probably failed due to a
 problem with the certificate (it might be expired, or the name might
 not match the domain name in the URL).
If you'd like to turn off curl's verification of the certificate, use
 the -k (or --insecure) option.
Could not download data at '/private/var/folders/xj/r56vhxgj54zdp2w4zyx6vg040000gn/T/tmpYRBYCN/LHAPDF-6.1.6.tar.gz'.
Command "install pythia8 " interrupted in sub-command:
"install pythia8" with error:
InvalidCmd : Installation of lhapdf6 failed.

Can someone help me?

Thanks