Hello,
The payment in installments is not available in wplms, however you can set the subscription payment. For example if you set the subscription to $5 per month then the users will have to pay $5 per month to continue the course. This setting is present in the woocommerce product settings.
In wplms there is also variable pricing option available in which you can set different prices for the same course but with different duration, number of course/quiz retakes, enable certificate/badge for the course, etc. This is present in the wplms woocommerce plugin, refer:
http://vibethemes.com/downloads/wplms-woocommerce/
You can add subscription from here: Edit the product in the pricing section and add the subscription, refer:
http://prntscr.com/a6hk6z
if you want automatic deductions and renewal of subscription :
follow :
https://wplms.io/support/knowledge-base/wplms-woocommerce-subscriptions-addon/
if not then simply enable the subscription options added by wplms in product settings .Make sure that the course is associated to product :
http://prntscr.com/m7tder
Thanks,