[capink]

This can be automated by downloading the zip files into calibre plugins folder:

import os

from calibre.gui2.dialogs.plugin_updater import get_plugin_updates_available
from calibre.constants import (
    DEBUG, __appname__, __version__
)
from calibre.utils.https import get_https_resource_securely
from calibre.utils.config import config_dir

plugin_dir = os.path.join(config_dir, 'plugins')
exclude_update = []

def update_plugins():
    total_updates = 0
    for plugin in get_plugin_updates_available():
        if plugin.name in exclude_update:
            print(f'Skip updating plugin: {plugin.name}')
            continue
        print(f'Updating plugin: {plugin.name}')
        raw = get_https_resource_securely(plugin.zip_url, headers={'User-Agent':f'{__appname__} {__version__}'})
        plugin_path = os.path.join(plugin_dir, f'{plugin.name}.zip')
        total_updates += 1
        with open(plugin_path, 'wb') as f:
            f.write(raw)
    if total_updates:
        print(f'Updated {total_updates} plugins. Restart calibre now')
    else:
        print('No plugins updated')


if __name__ == '__main__':
    update_plugins()

After running the command, you will need to restart calibre. Also don't forget to backup your calibre plugins folder in case something goes wrong.