You need an Ansible box for this, ie a server where Ansible is installed and ssh connectivity between those 100 nodes.
Ansible box is a server where ansible in installed and connect other nodes using ssh.
Create a project folder.
Create a file that lists all nodes where this task is required to be executed.
Create an Ansible.cfg file and make sure it is pointing to inventory file which lists IP addresses of nodes.
Run the Ansible Adhoc command to fetch uptime.