Here are some basics. Dynamic VPN is supported on the Branch SRX series (100-600). There are 2 dynamic vpn licenses that come with it. If yiou need more cliens then you have to purchase additional licenses. Verify that the licenses ae installed:
lab@srxA-1# run show system license
License usage:
Licenses Licenses Licenses Expiry
Feature name used installed needed
....
dynamic-vpn 0 2 0 permanent
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Dynamic VPNs support Policy based VPNs only
Must be configured with XAUTH
Must use pre-shared keys for IKE Phase 1
Only aggressive mode can be used
A little concerned a to which series you are using which does not show the dynamic-vpn heirarchy. The following out was take from an SRX 240
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lab@srxA-1# run show version
Hostname: srxA-1
Model: srx240h-poe
JUNOS Software Release [12.1X46-D15.3]
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lab@srxA-1# edit ?
Possible completions:
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> dynamic-vpn Configure dynamic VPN
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