SRX with four ISP, Traffic can go out from Internal Work with FBF, but can not access untrust interface from outside ?

I am four ISP, I set four FBF input filter on the intrenal interface, traffic can go out.

But I ping the four ISP interface from outside, no echo reply, but i missing ?

I need to change from ssg to srx, i used PBR before, I only set pbr, I need to change to srx, what i need to config?