How to refresh PPPoE Internet connection if assigned private IP (OpenWRT)

Hello everyone

I am new to linux

I am using linux based Openwrt
I tried ask this question in OpenWRT forum, but there is no answer yet
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I am connecting to my internet provider through PPPoE connection

provider assigns me IP dynamically

but provider sometimes assigns private IP (10.x.x.x) instead of public
(I mean that my provider assigns randomly private or public IP)
here is my question

how can I configure openwrt to renew connection automatically if private IP is assigned ??
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I mean after connection established provider assigned me IP
openwrt checks that IP
if IP is private
openwrt closes connection (or reboots openwrt)
waits few minutes connects to provider again
until public IP is not assigned by provider
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I am using OpenWrt 19.07
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As I understand better way to do it is write some script in /etc/ppp/ip-up

thanks in advance :)